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The Automobile
Handbook

A Manual of Practical Information

for Automobile Owners, Repair

Men and Schools

Lf ELLIOTT BROOKES

Revised and Enlarged By

HAROLD P. MANLY

Author of "Automobile Starting and
Lighting.**

Subjects Arranged in Alphabetical Order and

Indexed

FULLY ILLUSTRATED

CHICAGO
FREDERICK J. DRAKE & CO.

Publishers

CHICAGO.

Preface to Fifth Edition.

The reason for the present complete revision
of Brookes^ Automobile Handbook is found in
the automobile industry itself, in the radical
changes and remarkable developments that have
taken place. The new principles, new types of
construction and the changes in operating con-
ditions have affected every part of the car. For
this reason it has been considered advisable, not
only to supplement existing information with de-
scriptions of new products, but to treat every
subject presented from the standpoint of pres-
ent-day ideas and developments so that the user
may not be confused by statements that appar-
ently conflict, as would be the case if the revision
had ended with the addition of new data.

A glance at present designs discloses many
changes, among them being the decrease in
cylinder diameters and the increase in number
of cylinders from four and six to eight and
twelve ; the growing popularity and importance
of the sliding sleeve engine ; the modern methods
of battery ignition applied to high speed en-
gines ; the development and adoption of vacuum
fuel feed, and many other details of equal
importance.

The universal use of electric lighting and
engine starting devices has made this subject of

6 The Automobile Handbook

importance second to none, and the present edi-
tion therefore covers the details of construction
and operation of all existing types and makes
that are in common use. With the use of the
electric generating system operated from the
car's engine has come the electric gear shift;
and along similar lines, though independent in
conception, the magnetic transmission.

Due to the fact that, for so many years,
Brookes' Automobile Handbook has been the
recognized authority in this field, the arrange-
ment of subject matter has not been altered and
nothing has been omitted that caused the pre-
ceding editions to attain their popularity. The
size of the volume has been kept within reason-
able limits because of the fact that the infor-
mation given has been presented in the smallest
possible space through the free use of illustra-
tions and the formulation of definite rules for
care and adjustment of devices used for ignition
and carburetion.

An examination of the pages will show that
no subject of importance to owners or repair-
men has been omitted, while details for the
proper upkeep and care of each component of
the modern gasoline automobile have been given.
Suggestions from users will be welcomed to the
end that the publishers may always keep the
value of the Handbook up to the high mark
attained in the past.

INTRODUCTION

Progress in the automobile industry in the United
States during the past ten years has been phenomenal.
The mechanical propulsion of a wheeled vehicle along
an ordinary road is not by any means a new idea.
History tells us that speculations upon the possible
road use of **fire, and steam engines" were made by
Roger Bacon (1214-1294), and in the year 1619 a pat-
ent was granted in England to Bamsay, which had as
a part of its subject "drawing carts without horses.'^'
Many attempts were made from that time on to perfect
a self-propelling road vehicle, using steam as the pro-
pelling force, but it was not until the end of the year
1883 that Delamare-Debouttville constructed what is
thought to be the first gas tricycle which actually ran
on a public road. The general employment of gasolino
motors is due to two Frenchmen, Levassor, and Pan-
bard, who in 1889 exhibited in Paris a tram car having
a Daimler motor. Since then the development of the
gasoline motor car has been remarkable, due no doubt
to the fact that some of the best engineering talent in
the world has been, and is at present being directed
toward the perfection of the various types of auto-
mobiles, and it is entirely within the bounds of reason
to expect that a machine requiring so high a grade of
talent for its design and construction, should in its
operation be under the care of a skilled and reliable
chauffeur, one who not only understands the principles
of operation of each and all of the various parts
which go to make up the whole, but who also is com-
petent in case of minor accidents on the road, to make
such repairs as will enable him to proceed. He also
should be able to make such adjustments, and give the
machine such care as to reduce the expense of main-
tenance to a minimum. It is with a view of assisting
owners and drivers of automobiles, in fact all who are
in any way interested in a study of this remarkable,
and at the same time most useful machine, that the
Automobile Hand Book has been rewritten and revised,
thus bringing it strictly up to date, and in touch with
modern practice in the art of automobiling. While a

8 The Automobile Handbook

considerable portion of the subject matter found i
former editions of the book has been retained for tl
reason that it is standard, by far the larger portion <
the volume is new matter, and embodies the most recei
improvements in automobiles, together with instructioi
concerning their care and operation. Each part of tl
machine is thoroughly treated upon, and its constru
tion and the principled' governing its operation are e:
plained and illustrated in detail. While the gasolii
motor with its various accessories naturally occupi(
the major portion of the book, still a considerab'
space is devoted to steam, and electric motor car
Special attention is given to ignition mechanism h
eluding the various types of carbureters, magneto
etc., all being clearly described and illustrated. Tran
mission apparatus of all kinds is dealt with in detaj
Wheel construction recfeiyes a large share of attentio
and the important subject of tires is freely discussc
A large space is given Itb repair work in the she
and garage. As the subject of state license laws coi
templating the appearance of the chauffeur before a
examining board is one in which all motorists ai
vitally interested, this book will prove to be a reliab!
and trustworthy guide to all persons taking sue
examinations.

Note — The author gratefully acknowledges his ii
debtedness to the following named gentlemen, coi
suiting engineers, and authors of standard works o
engineering subjects:

Oscar C. Schmidt, consulting editor American Tes
Book Co., author of Practical Treatise on Automobilei

Paul N. Hasluck, author of Construction of Moder
Motor Cars.

The International Text Book Company, Scranton.

-iJ

The Automobile Handbook.

Acetylene Gas. The gas used in gas lamp;s
is generated by water, in minute quantities,
dropping on acetylene (carbide of calcium);
the gas thus formed pasSfes from the generating
chamber into the body of the lamp and is con-
sumed at the lava tips, which are placed in
front of a highly polished mirror. The genera-
tors in some cases are separated from the lamp
itself and placed on the dashboard, or under the
hood, a rubber hose conveying the gas to the
lamp.

The interior of the carbide chamber or bas-
ket being more or less in contact with the water
distribution apparatus, the parts of both appa-
ratus are liable to clogging by the formation of
lime residue in the generation of gas. If this
residue is allowed to collect, it will have to be
removed with a chisel, which is a ticklish opera-
tion in a light construction like that of a gen-
erator, especially around the water valve or
its outlet. Acids are sometimes used to remove
the deposit, but as they eat the metal, their use
should be prohibited. The basket and pot
should be thoroughly washed out after each run

10 The Automobile Handbook

with water, the water outlets being cleaned
with special brushes, when these are obtaina-
ble, or by wires, removing all traces of lime.
The water valve should be scraped and tested
to see whether it seats properly, care being
taken not to damage the valve or its seat in so
doing. While the valve is dismounted for clean-
ing it would be well to see that its stem is
straight, and that it works with some ease in the
threaded portion attached to the water chamber.
The gas valves should be cleaned and should
seat snugly, so that there will be no leakage
past them. This applies also to the gas valves
on the lamps.

The best position for the generator is on the
runlfing-board just back of the change-gear
quadrant, and sufficiently far out from the
frame to allow a free circulation of air ail
around it. The generator will keep cool in this
position and will perform its work to the best
advantage when properly cooled.

The system of acetylene gas lighting that is
generally used on cars having this source of
illumination is that making use of tanks in
which the gas is stored under compression.
These tanks are designed to hold 40, 60 or 100
cubic feet of gas and from them the illumin-
ant is carried to the various lamps through
tubing. Attachments are furnished by means
of which the lairfps may be lighted, dimmed or
extinguished from valves and buttons located
en the dash or cowl of the car.

The Automobile Handbook 11

Acetylene Lamp System — Care of. As there
is little night running during the winter
months, the acetylene lighting system is more
or less neglected, the generator being left with
stale or partially used carbide in the chamber,
and the residue being allowed to clog up the
water port and the waste ports. The rubber
lamp connections and gas-bag suffer also by de-
terioration as well as the burners and gas
valves. For the proper maintenance of the sys-
tem, strict cleanliness should be maintained at
all times, and the various parts should be ex-
amined and replaced from time to time as nec-
essary. The results of neglect are seen every
spring in lime deposits which have to be rpn^ov-
ed by means of a cold chisel, in porous connec-
tions and in clogged burners which resist the
cleaning wire and necessitate the scraping of
the burners. By following the accompanying
directions, the automobilist can depend on hav-
ing his lighting system in good shape whenever
he desires to use it.

Add Solutions. The electrolyte, or solution
used in storage battery cells, is made by pour-
ing sulphuric acid into distilled water until the
specific gravity becomes 1.25. The solution be-
comes extremely warm and should not be used
until its temperature is about 60 degrees.

Active Coil, or Conductor, A coil, or con-
ductor, conveying a current of electricity.

Adams Revolving Cylinder Motor. The
Adams motor rated at 50 horse power has a five

12 The Automobile Handbook

cylinder engine with a bore and stroke of 5^
and 5 inches. In this motor the crankshaft is
mounted vertically and has but one throw, the
same as ordinarily used for a single-cylinder
engine. This crankshaft is stationary — ^it never
revolves, but the five cylinders revolve around
it, as does the front wheel of a motor car on
the steering spindle. The car is without a radi-
ator, being an air-cooled machine; as the mo-
tor cylinders revolve, a cooling fan is not
needed. It is without a muffler, each cylinder
exhausting directly into a box which incloses
the motor. The motor is directly above the
transmission set, and as the motor is without
a flywheel of any sort, it has been necessary for
the designer to carry the double cone clutch
within the selective gear set. The drive from
the revolving cylinders to the gear-set is
through a bevel gear attached to the base of
the revolving crank case, and which meshes
with a bevel gear on one of the transverse
shafts of the transmission. From the transmis-
sion to the rear axle, a chain drive is employed.
This car is without a float feed carbureter, but
uses instead, a pump to maintain a gasoline
level in a chamber in which a spraying nozzle
and an air valve complete the carbureter. In-
stead of controlling the motor speed by advanc-
ing or retarding the spark, and opening and
closing the throttle, it is done by controlling
the length of time each intake valve is held
open. This motor has but one cam to open a2

The Automobile Handbook

of the ten valves. This earn being in two parts,
it is possible to shift one, thereby varying the
length of opening given a valve, and allowing
a part of the mixture drawn into a cylinder to
escape during a compression strobe, so that the
explosive pressure can be varied from 90 lbs,
to 0, and the power of the motor, and its speed

.- w

Fig. \
Sectional View of Adams Motor

correspondingly varied. There is no branching
manifold to convey the mixture to ths cylin-
ders, neither is there an exhaust manifold.

In Fig. 1 is a sectional view of the motor with
its five cylinders designated respectively 1, 2, 3,
4 and 5, with five pistons shown in relative po-
sition. The crankshaft A has its one offset B.
As each cylinder makes, in unison with the

The Automobile Handbook

other four, two complete revolutions, it passes
through the four cycles of operation common
to any four-cycle engine — ^inspiration, compres-
sion, explosion, exhaust. No. 4 cylinder is
shown at the end of the out stroke, and the
other four at different parts of the stroke ; and
as each in succession occupies the position of

Fig. 2

Cam Diagram — ^Adams Revolving Cylinder Motor

No. 4, its piston will be at the end of the out
fltroke. When diametrically opposite to No. 4
they will be at the inner end of the stroke.
Thus, as the five cylinders bolted firmly to-
gether to a hublike crankcase revolve, the pis-
tons reciprocate in the cylinders, thus perform-
ing in perfect sequence, the four functions of
cycling. The valves are located in the cylinder

. The Automobile Handbook 15

heads and opened by rocker arms with push
rods paralleling the cylinders on their lower
sides. One diagram illustrates the single cam
construction and valve operation. On the lower
end of the crankshaft is the two-part cam C,
CI — ^Pig. 2. The latter, shown in dotted line,
is the movable half for controlling the intake
Talve period of opening. Both parts of the
cam are stationary. On each of the five cylin-
ders is a push rod P, the inner end of which has
a peculiar foot P2 pivoted on the crankcase
with the curve portion bearing upon the cam,
and the short straight arm connected with the
push rod P. As the cylinder revolves, the
rounded foot follows the contour of the cam,
which has been designed so that the four cycles
follow one another in order as they do in a four-
cycle vertical engine.

The. principles of construction and opera-
tion of the motor just described are similar to
those found in aeronautical work, such as the
Gnome and other types of revolving motors. In
all of these types the crankshaft is stationary
and the cylinder unit revolves. The power for
driving is secured by connections on the cylin-
ders. As a general rule, these revolving motors
are started from rest by revolving the propeller
blades by hand until the first firing stroke is
secured. The valve mechanism will differ ac-
cording to the make of motor. In many cases
the fuel mixture is introduced through hollow
shafts and castings leading to the cylinders.

The Automobile Handbook

Air. Air consists, by weight, of oxygen 77
parts and nitrogen 23 parts; by volume, of 21
parts oxygen and 79 parts nitrogen. One pound
of air at atmospheric pressure, and 70 degrees,
Fahr., occupies 13.34 cubic feet of space. One
cubic foot of air weighs 1 1-7 ounces.

TABLE 1.

PROPERTIES OF COMPRESSED AIR

Oomp. in
Atmo»
pheres.

*Mean
Pressure.

Temp, in^

Degt^s

Fah.

*<}augQ
Pres-
sure.

'Absolute
Pressure.

'Isother-
mal Pres-
sure.

1.68

2.02

2.36

2.70

3.04

3.38

3.72

4.06

4.40

4.74

5.08

5.42

5.76

6.10

7.62
10.33
12.62
14.59
16.34
17.92
19.32
20.57
21.69
22.76
23.78
24.75
25.67
26.55

14.7

145

24.7

178

29.7

207

34.7

234

39.7

252

44.7

281 ,

49.7

302

54.7

324

59.7

339

64.7

357

69.7

375

74.7

389

79.7

405

84.7

420

89.7

30.39

39.34

48.91

59.05

69.72

80.87

92.49

104.53

116.99

129.84

143.05

156.64

170.58

184.83

♦In pounds per square inch.

Air Properties of Compressed. Table 1 gives
the Mean pressure. Temperature in degi'ees
Fahr., Gauge pressure. Absolute pressure and
the Isothermal or heat pressure of air under
compression of from I'to 6.10 atmospheres.

As energy in the form of power must be used
to compress air to any desired pressure, so is
energy in the form of latent or stored heat
given up by the air during the operation of
compression. This heat consequently increases
the pressure resulting from the compression,

The Automobile Handbook 17

but not directly in proportion to the degree of
compression in atmospheres.

This increase of pressure above the Adiabatic
or calculated pressure is known as the Isother-
mal or heat-pressure. As the values of this
pressure cannot be calculated by the use of
ordinary mathematics, but involve the use of
logarithms, Table 1 gives these values for each
degree of compression given.

Many persons who are not familiar with the
properties of gases, estimate the pressure re-
sulting from the compression to a given number
of atmospheres, as the number of atmospheres
multiplied by the atmospheric pressure, which
at sea level is taken as 14.7 pounds per square
inch.

This assumption is erroneous and will often
lead to grievous mistakes in motor design,
generally giving too much compression, which
results in premature ignition, commonly known
as backfiring. Such methods of calculation
would be true if the air, after -compression, was
stored in a reservoir and allowed to cool, but
under no other conditions.

Air, Relation of to Gasoline. Owing to the
fact that automobile gasoline is composed of
various percentages of the several available
fractions of hydrocarbon distillates, it is not
possible to fix an exact basis for the relative
proportions of air to fuel. However, the aver-
age carbureter is capable of altering the ratio
of air to fuel over broad ranges, and it is not
necessary to know the exact ratio in order to

18 The Automobile Handbook

attain the best results. But it is necessary to
approximate an average ratio as nearly as pos-
sible in designing and adjusting carbureters in
order to allow for these variations up and
down.

The mixture becomes explosive when 10,000
volumes of air dilute one volume of gasoline,
but the best results follow when the ratio is
one volume of liquid gasoline to 8,000 volumes
of air. With one of gasoline to 3,500 of air the
mixture is non-explosive.

The proper proportions, from a theoretical
standpoint, are not always best for practical
use because a mixture slightly weaker than the
one found by calculation is more economical in
the use of gasoline. Such a mixture, of course,
reduces the power slightly, but the proportion
of power lost is much less than the proportion
of gasoline saved. Because of the differences in
speed of the mixture and the differences in the
volume being admitted to the engine, it is almost
impossible to secure a proportion that will be
uniformly satisfactory over a range of all engine
speeds. A larger volume of mixture, at a slow
speed, may be required in ascending a hill at
ten miles per hour than in traveling on a level
road at three times this speed. In the latter
case, the velocity of the mixture will, however,
be much greater. It is best to secure a mixture
that will give satisfactory results from the
standpoint of power at low and medium speeds
rather than at high.

The Automobile Hamdbook 19

Air, Relation of in Gasoline Mixture. Gas-
oline is a somewhat uncertain mechanical mix-
ture of several hydrocarbon (fractional) distil-
lates, in which the compound *'hexane'' is sup-
posed to be the major portion. This compound
answers to the formula €« Hj^, the products of
combustion of which will be C O2 + C 0 + HgO,
in which C O will not be found if the combus-
tion is complete. A final expression of complete
combustion will be as follows :

2 CeHi, X 19 O2 = 12 C O2 + 14 H2 0.
Taking into account the atomic weight of the
elements, the volume of air required in the com-
plete combustion of 1 pound of hexane may be
set down as follows — atomic weight of the ele-
ments involved:

Carbon (C) : 12

Hydrogen (H) 1

Oxygen (0) 16

The molecular weight of C^ H14 = 6 X 12 +
14X 1 = 86 ; the required oxygen will weigh
(molecular) 19X16 = 304; the ratio of the
compound hexane, then, to the combining oxy-
gen will be

304

Ratio = = 3.54, nearly.

86
Considering 1 pound of hexane, the weight
of oxygen required for its complete combustion
will be equal to the ratio as above given, i.e.,
3.54 pounds, nearly.

Since the oxygen is taken from the air, It is

20 The Automobile Handbook

necessary, tp. consider dry air in the attempt to
detern^ine as to the weight of the same. This
air, under a pressure of 1 atmosphere, and at a
temperature of 60 degrees Fahrenheit contains
0.23 pounds of oxygen, hence the required air=;

3.54

— — =z 15.39, in pounds.
.23

Afr Resistance, Horsepower Required to
Overcome. The power required to move a plane
surface, such as the vertical projection of an
automobile, against the air, does not become of
much importance until the car attains a speed
of 10 to 12 miles per hour, when it becomes an
important factor.

The horsepower required to propel an auto-
mobile against the resistance of the air may be
approximately calculated by the following for-
mula. Let V be the velocity of the car in feet
per second, and A the projected area of the
front of the car in square feet — this may be as-
sumed as the height from the frame to the top
of the body multiplied by the width of the seat
at the floor line of the car — ^let H.P. be the
horsepower required to overcome the air re-
sistance, then

V^X A

H.P.=

240,000

To simplify the use of the above formula,
Table 2 gives sDPeds in miles per hour corre-

The Automobile Handbook

spending to their respective velocities in feet
per second and also cubes of velocities in feet
per second.

TABLE 2.

CUBES OF VELOCITIES IN FEET 1»BB SBCOND.

Miles per

Hour of

Car.

Feet per
Second.

Cube of

"V elocity

in Ft. per

Second.

Miles per

Hour orf

Car.

Feet per
Second,

Cube of

Velocity

In Ft. ler

Second,

10.2
13.6
17.2
20.4
27.2

15
20
25
30
40

3,375

8,000

15.625

27,000

64,000

34.0
40.0
47.7
54.4
61.3

50
60
70
80
90

125,000
2164)00
343,000
512,000
729,000

To ascertain approximately the horsepowei
that will be necessary to drive a car against 8
vrind of known velocity, the speed of the cai
must be added to that of the wind, and the re-
quired horsepower may be found either by use
of the formula given or by reference to Table
3, which gives the horsepower per square foot
of projected surface required to propel a cai
against the resistance of the air, with varying
speeds in miles per hour or velocities in feel
per minute.

TABLE 3.

HORSEPOWER REQUIRED PER SQUARE FOOT OF SURFACE, TO MOYB
A CAR AGAINST AIR RESISTANCE.

Miles per

Hour of

Car.

•

Feet per
Second.

Horse-
power per
Square
Foot of
Surface.

Miles per

Hour of

Oar.

Feet per
Second.

Horse-
power rer
Square
Foot of
Surface.

.10
15
20
25
30

14.7
22.0
24.6
36.7
44.0

0.013

0.44

0.105

0.205

0.354

40
50
60
80
100

58.7

73.3

87.9

117.3

146.6

0.84
1.64
2.83
6.72
13.12

The horsepower given by the formula and
Table 3 simply refers to the additional power

22 The Automobile Handbook

necessary to overcome air resistance and not to
the actual power required to propel a car at a
given speed ; this is entirely another matter.

Alcohol. There are two kinds of alcohol;
methyl, or wood, alcohol, CH4O, and ethyl, or
grain, alcohol, CzELqO, The former has been
found objectionable for use in internal-combus-
tion engines, because it apparently liberates
acetic acid, which corrodes the cylinders and
valves.

As alcohol is a fixed product, and the same
the world over, it has a great advantage as a
motive power over gasoline and other petro-
leum products. Denatured alcohol contains
4,172 heat units per pound as compared to
18,000 for gasoline, and, as its cost is higher,
this fuel would not seem practicable from an
economic standpoint. By mixing the alcohol,
however, with a high grade of gasoline, its price
is lowered, and the number of heat units per
pound greatly increased. Mixtures containing
50 per cent alcohol have a calorific power of
11,086 heat units per pound, and as it has been
found by numerous tests in France that it re-
quires no more of this mixture than of gasoline
to develop a certain power, its efficiency is con-
siderably greater, reaching a value of 24 per
cent as compared to 16 for the gasoline motor.
In some recent experiments in France with a
motor specially constructed for the use of alco-
hol, the consumption was lowered to 0.124 pound

The Automobile Handbook 23

per horse power, using 50 per cent earburetted
alcohol.

Grain, or ethyl, alcohol has a specific gravity
of .795, and may be obtained by distillation
from corn, wheat, and other grains, potatoes,
molasses, or anything containing sugar or
starch. When pure, it absorbs water rapidly
from the air, more rapidly in fact than it loses
its own substance by evaporation; but when
diluted to the proportion of about 85 per cent,
alcohol and 15 per cent, water, it evaporates
practically as if it were a single liquid and not
a mixture. In France, it is denatured for mo-
tor purposes by the addition of 10 liters of 90^
wood alcohol, and 500 grams of heavy benzine,
to 100 liters of 90° ethyl alcohol. In Germany,
benz6l is added to the extent of 15 per cent, for
denaturing, no wood alcohol being used. In
the United States the so-called "denatured"
alcohol, which is that used in the arts and in-
dustries, is composed of ethyl or grain alcohol,
to which have been added certain diluents cal-
culated to make it unfit for drinking. The In-
ternal Revenue regulations specify that to 100
volumes of ethyl alcohol there must be added
10 volumes of methyl (wood) alcohol and one-
half of one volume of benzine, or to the same
quantity of ethyl alcohol n:ust be added 2 vol-
umes of wood alcohol and one-half of one vol-
ume of pyridine bases.

As compared with gasoline as a fuel for in-

24 The Automobile Handbook .

ternal-combustion motors, alcohol exhibits sev-
eral striking peculiarities.

First, the combustion is much more likely to
be complete. A mixture of 90° alcohol vapor
and air will burn completely when the propor-
tion varies from 1 of the vapor with 10 of air
to 1 of the vapor with 25 of air, thus exhibiting
a much wider range of proportions for combusti-
bility than is the case with gasoline. As the
combustion is complete, the exhaust is practi-
cally odorless, consisting only of water vapor
and carbon dioxide.

Second, the inflammability of an alcohol mix-
ture is much lower. This is due partly, no doubt,
to the presence of water in the alcohol, which
is vaporized with the alcohol in the engine and
must be converted into steam at the expense of
the combustion.

For these reasons, the compression of an al-
cohol mixture is carried far above that permis-
sible with a gasoline mixture, without danger
of spontaneous ignition. The rapidity of com-
bustion of alcohol in an engine is considerably
less than that of a gasoline mixture, and for this
reason the speed of alcohol engines must be
somewhat slow.

The facts that alcohol of sufficient purity for
use in engines can be produced from the waste
products of many of the country's industries,
and at a nominal cost, and that many thousands
of acres of land, unfit for the cultivation of
first-class grain, etc., may be utilized for the

The Automobile Handbook 25

production of vegetable matter rich in the ele-
ments which form alcohol upon fermentation,
lead to the supposition that within a few years,
or as soon as there is a sufficient demand for
alcohol to warrant the erection of special dis-
tilleries, it may be purchased at such a low price
that it will not only be commercially possible,
but will in a measure force gasoline and other
petroleum distillates from the field.

A carbureter designed to operate with alcohol
can always be used with gasoline, but the re-
verse conditions are not true, that is, a gasoline
carbureter will not operate successfully with
alcohol, except in some rare instances. Alcohol
evaporates slower than gasoline and its time of
combustion is much slower, but it maintains its
mean effective explosion pressure far better
than gasoline.

Explosive motors fitted with alcohol carbu-
reters make far less noise than when using gaso-
line as a fuel, due to the slower burning of the
explosive charge, they also make less smoke
and smell.

The jet or spray of a float-feed carbureter will
have to pass nearly 40 per cent, more liquid
fuel than when using gasoline, consequently the
opening in the nozzle must be proportionally
larger.

A carbureter using alcohol must be fitted with
some form of device to heat the alcohol to en-
sure rapid evaporation — this is usually done by

26 The Automobile Handbook »

surrounding the mixing-chamber with an ex-
haust-heated jacket.

The same quantity of alcohol will only take
a car two-thirds of the distance that gasoline
will, hence greater storage capacity would be
needed on a car using alcohol as a fuel.

An explosive motor designed to use alcohol
requires a greater degree of compression than a
motor of the same bore and stroke designed to
use gasoline, in order to develop the same
power.

Alternating Current, Use of. It is not only
useless but absolutely injurious to attempt t>
charge^ a storage battery directly from a:i alter-
nating current circuit. This can only be done
by means of a rotary converter, which is in
reality a motor-generator, receiving its power
from the alternating current and transforming
it into a direct current which can be used to
charge the batteries.

Aluminum. A soft ductile malleable metal,
of a white color, approaching silver, but with a
bluish cast. Very non-corrosive. Tenacity
about one-third that of wrought iron. Specific
gravity 2.6. Atomic weight 27.1. It is the
lightest of all the useful metals, with the excep-
tion of magnesium.

Aluminoid, Composition and Use of. Alu-
minoid is composed by weight of 60 parts alu-
minum, 30 parts tin and 10 parts zinc. It has a
tensile strength of about 18,000 pounds and is a
very suitable material for crank chambers, gear

The Automobile Handbook

ceises and small brackets, bting light, extremely
ductile and readily machined.

AliuniniUE Solder, The following formula is
±or a solder which will work equally well with
filuminum or aluminoid : Tin, 10 parts — cad-
zaium, 10 parts — ^zine, 10 parts — lead, 1 part.
The pieces to be soldered must be thorouglily
cleansed and then put in a bath of a strong solu-
tion of hyposulphate of soda for about two
hours before soldering.

Alloys, Composition of. The proper compo-
sition of alloys of metals for the bearings and
other parts of an automobile is a very important
. consideration from a constructive standpoint.
Table 4 gives the composition of various alloys
• of metals and also solders for different uses.

■5-

Brass, foe IlKht work, other thaii

BroBie flaaiiiCT. to stana liraKlHg. . .

Metal to eipKad Id cooling, tor

■i

fipMu-v. S..fl .... ._. . .

...

■■■

It should be understood that no definite rule
can be given for the proportioning of any one
alloy for the reason that a, slight change in the

•£i

The Atitomobile Handbook

amount of one or more of the elements may
the metal exactly for some proposed use, wh
porportion only slightly different might give
satisfactory results.

Ammeter, Construction of. Ammeters
automobile use are constructed on the princ

of the D'Arsonval galvanometer with a per
nent magnetic field. The special feature i
small oscillating coil mounted on cone-p
bearings surrounding a stationary armal
which is centrally located between thp ji
pieces of a permanent magnet, with a poii
or index-finger which indicates the electr
variations on a graduated scale.

The Automobile Handbook

The construction of an ammeter is fully
show in the two views in I^'^gure 3. The per-
manent magnets used in its construction are of
a special quality of hardened steel, made only
for this purpose and possessed of great mag-
aetic permeability. The pole-pieces, which are
of soft steel and well annealed, are attached to
the inside of the lower part of the magnet legs,
the joints between the pole pieces and the mag-

Fig. 4

net legs are usually ground to insure the full
efficiency of the magnetic circuit. The soft iron
core of the coil is for the purpose of rendering
uniform the magnetic field in which the coil
must oscillate. A coil of insulated wire is
wound upon the stationary armature at right
angles to its axis, in the same manner that
thread is wound upon a spool, and is short-cir-
cuited on itself, that is to say, the ends of the
wire forming the coil are connected together.
This coil of wire is for the purpose of choking

30 The Automobile Handbook

the magnetism induced in the stationary* arma-
ture by the oscillating coil, as it generates what
are known as eddy currents within itself, thus
making the instrument periodic, or dead-beat,
in its indications. Around the armature core
and outside the short-circuited coil of wire is
wound the active or oscillating coil and at right
angles to the direction of the winding of the
first coil. The oscillating coil consists of a num-
ber of turns of fine insulated copper wire, to
which the current is conveyed through the me-
dium of the controlling springs at each end of
the spindle, which is in two parts and con-
nected together by a suitable sleeve of insulat-
ing material, as shown.

The pointer or index-finger is made with a
boss or hub to go over the end of the spindle of
the active coil and also has an extension with a
small counterweight or balance, so that the
pointer may be accurately adjusted.

The only difference in the construction of a
voltmeter and an ammeter is that in the former
the active or oscillating coil is in series with a
high resistance, while in the latter it is con-
nected across the terminals of a shunt-block.
The voltmeter is in reality an ammeter, the re-
sistance serving to keep the amperage in step
with the voltage.

Reference to the three views, marked re*
spectively A, B and C in Figure 4, will show
clearly the principle of the operation of an
ammetev ur ^roltmeter, and the reason that they

The Automobile Handbook

icord^the current strength op pressure of an
ectric current accurately.
Ammeters are of two kinds, the double-beat
^pe, as shown in Figure 3, which indicates the
irrent strength or number of amperes flowing
I the electric circuit, without any regard to
le polarity of the terminals of the circuit, by
le pointer or index-finger moving either to the
ght or to the left of the zero position. The

/OLT-AMMETER

Fig. 5

ngle-beat tj^e of ammeter only records in
le direction, by the pointer moving from the
ft to the right of the graduated scale of the
istrument, consequently the polarity of the
irminals of this type of ammeter are marked
1 its outer casing and the polarity of the ter-
linals of the electric circuit must consequently
B determined before connecting them with the
fnmeter.

32 The Automobile Handbook

Ampere. The unit of electric current fl(
An ampere is that volume of current wh
would pass through a circuit that offered a
sistance of one ohm, under an electromot
force of one volt.

Ampere-houTy Definition of. The term i
pere-hour is used to denote the capacity o
storage or a closed-circuit primary battery
current. A storage battery that will keep
ampere lamp burning for 8 hours is said
have a 16 ampere-hour capacity. In a sim
manner an 80 ampere-hour battery would c
rate the same lamp 40 hours. The voltage c
battery does not enter into the calculation
its ampere-hour capacity.

Anti-Freezing Mixtures. If a solution of
cohol and water is used, the best results will
obtained by having it just strong enough
stand the lowest temperature to which i1
likely to be subjected in the climate wher-
is to be used.

The reason for this is that the alcohol evg
rates out from the solution, and the stronger
solution, the more there is to evaporate,
easier it evaporates, and the greater the in
ence of this evaporation upon the solution 1

The diagram shown on page 33 indicates
freezing points of various solutions of d(
tured alcohol, also of wood alcohol. From
diagram a solution may be selected which "
stand any temperature from 50® below zerc
40® above.

The Automobile Handbook

Other solutions may be made with ealeium
chloride (common salt), also the salts known as
potassium carbonate. These with water form a
solution that will stand zero temperatures, but
are not available where lower temperatures are
common.

4 * « R B 0 ! B 8 « .

' 8
s

■8

Non-Freezino Mixtures fob Radiators. In
cold weather, the circulating water, the oil,
and the carbureter require special attention.
If the car is to be run regularly during

34 The Automobile Handbook

the winter, it is advisable to use a
freezing mixture in the water-jacket. I
car is not to be used regularly, it ma;
be necessary to employ such a mixture, l
that case great care is necessary to prevei
water from freezing unexpectedly. If th
is kept in a barn, the water should be c
off completely after the car has been used
the drainage cock should be so located an
piping so arranged that there are no
pockets in which the water may freeze ar
struct the circulation. If the water free:
the pump, the latter is likely to be broken
the car is started the next morning. If
freezes in the water-jackets, it will burs
jackets unless they are made of copper,
the car is left standing for an hour or so, *

Proportions of Glycerine, Alcohol i

Water.

Freezing
Point

Glycerine and
Alcohol (equal parts)

28° above

15%

15° above

20%

10° above

24%

5° above

28%

Zero

30%

5° below

33%

10* below

36%

The Automobile Handbook 35

or lap robes may be thrown over the radiator
to check the cooling; this is cheaper and safer
than leaving the motor running.

The two substances most used to prevent
freezing are glycerine and calcium chloride. A
30-per-cent solution of glycerine in water
freezes at 21° F. ; and a solution of one part of
glycerine to two parts of water is safe from
freezing at 10° or 15° F. ; 40-per-cent solution
freezes at zero. A small amount of slaked lime
should be added to neutralize any acidity in the
solution. Glycerine has the objection that it
destroys rubber, and the solution fouls rather
quickly.

A cheaper mixture, and one preferable where
the temperatures encountered are likely to be
below 15° or 20° F., is a solution of calcium
chloride. This must be carefully distinguished
from chloride of lime (bleaching powder),
which is injurious to metal surfaces. Calcium
chloride costs about 8 cents a pound in bulk,
and does not materially affect metals except
zinc. A saturated solution is first made by add-
ing about 15 pounds of the chloride to 1 gallon
of water, making a total of about 2 gallons.
Some undissolved crystals should remain at
the bottom as evidence that the solution is sat-
urated. To this solution is added from 2 to 3
gallons of water, the former making what is
called a 50-per-cent. solution. A little lime is
added to neutralize acidity. A 50-per-cent so-
lution freezes at — 15° F.

36 The Automobile Handbook

Whether glycerine or calcium chloride is
used, loss by evaporation should be made up by
adding pure water, and loss through leakage by
adding fresh solution. In using the chloride,
it is important to prevent the solution from ap-
proaching the point of saturation, as the chlo-
ride will then crystallize out and clog the radi-
ator, besides boiling, and failing to cool the
motor. A 50-per-cent. solution has a specific
gravity of 1.21, and should be tested occasion-
ally by means of a storage-battery hydrometer.
Equally important is it to prevent the water
from approaching the boiling point, whatever
the density, as boiling liberates free hydrochlo-
ric acid, which at once attacks the metal of the
radiator and cylinders.

A solution of two parts of glycerine, one part
of water, and one part of wood alcohol has been
recommended, which is said to withstand about
zero temperature.

Certain mineral oils used for the lubrication
of refrigerating machinery are recommended
for cooling, because they remain liquid at very
low temperatures. They are not particularly
good heat conductors, however, and will not
keep the motor as cool as the water solution.
If the oil is used, it must be cleaned from the
radiator by the use of kerosene and oil soap,
before water can again be used effectively.

As regards lubrication, the principal danger
is that the oil will thicken from the cold so that
it will refuse to feed. This is avoided by usingx

The Automobile Handbook 37

cold test oil, which remains liquid at lower tem-
peratures than ordinary oil, or by adding to the
ordinary oil some kerosene or gasoline, and in-
creasing the feed. If the oil tank is located
close to the engine, it will remain liquid, even in
quite cold weather. But unless the car has been
kept in a warm place over night, the bearings are
liable to run dry before the car has warmed up.

Cooling Solutions — For Winter. Kadiators
are costly, delicate and composite in construc-
tion, the latter due to the plurality of metals in
their make-up, hence electrolytic action takes
place, due to the difference of potential nat-
ural to the different metals immersed in a saline
bath. Therefore great care should be exer-
cised in the preparation of anti-freezing solu-
tions made up of calcium chloride (common
salt and water). Any approach to the satura-
tion limit is attended with danger of precipita-
tion. The saturated solution is ascertained at
60 degrees F., and increasing the temperature
increases the capacity of the water to hold the
salts in suspension.

On the other hand, the Ohmic resistance of
a solution is lowest at about half saturation.
To sum up, it is experience that counts, and
it is still a question as to the extent to which
saline solutions can be used with safety. Of
course there is no solution as good as water
alone, but unfortunately water will expand
when it freezes, and it will freeze on small prov-
ocation in a radiator. Oil as a cooling medium

38 The Automoiile Handbook

has points in its favor which some authorities
claim render it more efficient than water, as
for instance it has a higher boiling point, about
double that of water, and as a result the oil
will not waste away except by leakage. The
heat exchange occurs at a higher temperature,
thereby increasing the efficiency of the motor.
Then also the area of radiating surface may be
smaller, with a conesquent decrease in weight,
while the work of the fan is rendered of less
importance. A light, thin, pure mineral oil is
the most reliable. Animal, and vegetable oils
are more apt to become rancid, the acid in them
also attacks the metal of the radiator.

Armatures, Dynamo. The armature, or re-
volving member of lighting dynamos, is com-
posed of a core made from wrought iron or mild
steel. It is customary to make this core by as-
sembling a sufficient number of thin plates
made in the form of the cross section of the
core, these plates being covered with an insulat-
ing composition and then fastened together on
the shaft. This construction prevents the for-
mation of harmful **eddy currents'' within the
metal.

The assembled core has a number of slots run-
ning lengthwise of its body and in these slots
are placed the armature coils or winding of in-
sulated wire. The coils are then connected to
a commutator mounted on one end of the shaft
in such a way that the current generated may
be collected by the brushes.

The Automobile Handbook

Armatures, Slotted and Shuttle Types of.
An armature is the rotating part of a dynamo
or electric motor which generates electricity or
develops power.

Fig. 6 *"

The armature shown at right of Fig. 6 is
known as the Siemen's H or shuttle type and is
the simplest form of wire-wound armature
known. The current given by this form of
armature is of the alternating type and is con-
verted into a direct-current, when desired, by
means of a two-part commutator on the arma-
ture shaft.

The slotted type of armature shown at the
left of Fig. 6 has a more intricate sys-
tem of winding than the shuttle type just de-
scribed. It has, however, a far greater elec-
trical efficiency and gives off a steadier current
than the shuttle type. It is the form most gen-
erally used for automobile and street railway
motors. Like the shuttle type of arinature, the
current generated by the slotted type of arma-
ture is alternating, and is converted into a di-
rect current by means of a commutator of very
complicated form.

40 The Automobile Handbook

Assembling a Car. In assembling the car the
engine had best be put together first. When
putting the pistons in their respective cylinders
see that the splits or joints in the piston rings
are not in line, but are spaced evenly around
the piston. See that all parts are thoroughly
clean and that no grit, or stray strands of waste
happen to be caught on any projection. All
nuts and bolts should be screwed tight and the
jaws of the wrench should be properly adjusted
to them, that the corners of the nuts and cap
screws may not be rounded off. Insert the cot-
ter pin after each nut has been screwed home.
In joints where packing is required the old
packing may be used if it is in good shape.
Joint faces should, of course, be perfectly clean.
A stout grade of manila wrapping paper soaked
in linseed oil will make an excellent packing for
crankcase and other joints having a good con-
tact surface.

While the engine is being reassembled it will
be found advantageous to check up the valve
timing. To do this, turn the fly-wheel until
the inlet valve plunger of No. 1 cylinder just
touches the lower end of its valve stem. At this
point the line on the fly-wheel indicating ** Inlet
No. 1 Open'* should coincide with the pointer
on the engine base. If the contact between the
valve stem and the plunger is made before the
mark on the fly-wheel lines up with the pointer,
the valve opens too early. In most cars the
adjustments may be made by the screw cap and

The Automobile Handbook 41

lock-nut on the plunger. As the valve stems are
lowered by repeated grindings of the valves,
the plungers require adjustment occasionally
to compensate for this movement. Insert a
piece of paper between plunger and valve stem,
and by lightly pulling on the paper the time of
contact and the moment of release may be de-
termined to a nicety. When the paper is held
tightly, a good contact is assured, and the mo-
ment the paper becomes loose and can be moved
about, the contact is broken. In many cars the
reference or index mark on the engine bed is
omitted; in this ^se the markings on the fly-
wheel must be brought directly to the top. The
other inlets and the exhaust valves should then
be similarly checked up and adjusted.

Most cars base the valve setting on a 1-32
inch clearance «pace between valve stem and
plunger rod when the valve is closed. This
may be taken as the minimum amount, and
should not be increased. A larger amount of
clearance will cause the' exhaust valve to open
too late, and, the exploded gases not being en-
tirely expelled, the power of the motor will be
impaired. This clearance is necessary to allow
for the expansion of the valve stem when it be-
comes heated.

Too much stress cannot be laid on the neces-
sity of going about the work in an orderly and
methodical manner. A mechanic who leaves
parts lying about carelessly will rarely be found
a good one, and certainly he is not a proper

42 The Automobile HandbooJc

model for the amateur to copy. With the proper
circumspection, then, and with a little ^Tiorse
sense^^ in applying the directions to his par-
ticular make of car, the amateur owner should
have no difficulty in making a good job of over-
hauling, thus bettering the condition of his ma-
chine and at the same time acquiring a valua-
ble stock of knowledge for the future.

Automobile Driving. When on the open
road, away from cities or towns, the fol-
lowing rules should be borne in mind. (1)
Drive with moderate speed on the level, slow
speed down hill, and wide open throttle for
hill climbing, or getting up speed only. (2)
The condition of the road should be noticed,
the presence of mud or dust thereon furnishing
sufficient reason for slowing down .somewhat
for the sake of other road users. (3) The or-
dinary rules of the road regarding the negotia-
tion of turns, and crossings, also the overtak-
ing or passing of other vehicles should be ad-
hered to, even though a lower rate of speed is
involved thereby. (4) A sharp lookout should
always be kept for traffic of all kinds, as well
as on approaching schools, churches, or public
buildings, and also for road signs indicating
danger, caution, etc. (5) When on the road
the autoist should show courtesy to other road
users. Courtesy in autoists is much appreci-
ated, and goes a long way toward removing
the prejudice which exists in many places
against automobiles.

Hie Automobile Handbooh 43

Gear — Changing. In changing gears the au-
toist should endeavor to have the motor and
car moving at nearly corresponding rates of
speed before the clutch is engaged. With the
planetary type of gear, changing is simple, and
drivers usually guess at the proper period at
which to make the change, any mistake in esti-
mating the rates of the car and motor being of
little consequence, as the bands will slip instead
of transmitting the shock to the gear. A simi-
lar action occurs in the case of individual
clutch or friction gears, but with the sliding
type severe strains and shocks have to be taken
up by the clutch, and are usually transmitted in
part to the gear if the clutch is not slipped.
What applies to the sliding type in general ap-
plies to the other types as well.

In changing from a lower to a higher gear it
will be necessary to speed up the motor by
means of the throttle or accelerator in order to
store enough energy in the flywheel to furnish
the work needed to accelerate the car to its
new speed. As the speed of the car increases
the higher gear should be engaged, the autoist
not being in too great a hurry to make the
change. The movement of the change gear le-
ver should be made quickly in order that the
car does not lose way. When changing from a
higher to a lower gear the change should be
made as quickly as possible before the car has
time to slow down. When climbing a steep hill
it should be ascended as far as possible on the

44 The Automobile HandbooTe

high gear by proper use of the throttle and
spark, and the change down to the lower gear
made as soon as the motor begins to labor or is
in danger of stopping. The presence of an
unusual number of passengers in the car will
affect its ability to negotiate grades which ordi-
narily are taken on the high gear, and the auto-
ist should remember this and not attempt to
force the car to travel on that gear with the in-
creased load, but resort to a lower gear.

Reversing — Backing Up. Among other things
connected with driving which is apt to l)e neg-
lected, is reversing, or driving a car backward.
Usually a car is never reversed for more than
a few yards at a time and the maneuvering in-
volved requires no great skill. Steering a car
when running backwards is diametrically op-
posite to that when running forward. A turn
of the wheel to the left steers the car in the
opposite direction to the right, and vice versa.
The usual mistake made in reversing is in turn-
ing the steering wheel too far, and describing
zigzags in th^' road as a result. The autoist
should reijBBMS^ that the reverse gear of a
sliding cha^^%ear should never be engaged
until the car lias been brought to a full stop.

Brakes, Proper Use of. Next to the motive
power in importance come the brakes. There
are a number of points regarding brakes that
every autoist should know and remember. First
and most important is the fact that brakes vary
in their effectiveness, and that freedom from dis-

The Automobile HandhooTc 45

aster depends upon the brakes being kept in
good condition and properly adjusted. Second,
while a brake may be perfectly satisfactory for
slowing down, it by no means follows that it will
bring a car to a stop as it should, nor hold the
car from going backward. Third, brakes
should be tested frequently with the car in
motion, the pedal or hand lever being applied
until the car slows down, or stops. The distance
covered in making this test should be noted,
and a greater distance allowed in making stops
on the road.

In applying brakes, the application should be
gradual, reducing the speed of the car as quickly
as possible without locking the wheels. As long
as the tires retain their grip on the road, the
powerful retarding action of the brake contin-
ues, but when the wheels are locked the brakes
have little or no effect, and the car will either
slide along, or skid, in either case being be-
yond the control of the driver. Should the
wheels become locked while descending a hill,
the brakes should be released until the wheels
are again revolving, and then reapplied gradu-
ally, until they act satisfactorily.

Brakes should be examined at regular in-
tervals in order to ascertain if the lining is in
good condition. If worn, the old lining should
be replaced with new. If the brakes are of the
internal-expanding type, the shoes may have
become worn, in which case they should be re-
newed. Toggle joints and adjusting nuts

46 The Automobile Handbooh

should be inspected, and any looseness taken up.
Brakes should be adjusted on the road, as any
improper adjustment of the equalizer bar will
have a strong tendency to make the car skid.
Both brakes should be adjusted alike, that the
braking force applied by the equalizer may be
transmitted to the wheels equally.

SmE Slip, or Skidding. If the rate of rota-
tion of a wheel is greater than the rate of ad-
vance over the road, the wheel loses adhesion
and thereafter it is just as easy for it to move
in one direction as in another.

The wheel can now slip sideways as easily
as it can slip forwards, particularly when it has
the rounded section slightly flattened, which is
the case with pneumatic tires. When traveling
straight ahead, and with the*motor out of gear,
skidding does not usually occur. A slight turn
given to the steering wheel checks the speed
and introduces a side pressure on both front
and rear wheels, due to the machine tending to
continue its path in a straight line. Generally
this side pressure will not cause skidding. If,
however, the motor be suddenly thrown in gear,
or the brakes suddenly applied, or, what
amounts to the same, a large turn is given the
steering wheel, the wheels find themselves
either rotating more than in proportion to their
advance, or advancing more than in proportion
to their rotation. This immediately causes a loss
of adhesion, which, once established, causes the
car to skid or side-slip.

The Automobile Handbook 47

Spark — Regulation of. Upon the proper use
of the sparking device depends the economy of
the motor, and in many cases the safety of the
driver. On some cars the sparking point on the
magneto is fixed, and the autoist controls the
car by the throttle only. There are a number
of cars in use which employ the battery in con-
nection with separate coils or a single spark sys-
tem, or a magneto on which the spark can be
regulated by the driver. When starting, the
spark should be retarded in the case of battery
ignition, to prevent backfiring, and slightly ad-
vanced to a certain point, depending on the
motor and magneto, in the case of magneto igni-
tion. "When it is desired to slow the motor
down below the point obtained by throttling
only, the spark is likewise retarded. In ordi-
nary running, a position of the spark lever can
be found which will give fair average results
through a considerable range of speed without
changing its position, and this position varies
with each motor, and can be found by experi-
ence. When a higher rate of speed is desired,
the throttle is opened and the spark advanced
gradually. If a grade is to be negotiated it
should be ''rushed" if possible, the throttle be-
ing opened full and the spark well advanced
until the motor begins to slow down and
*' knock," when the spark should be retarded to
correct this. The autoist should always keep
the spark as far advanced as possible, without
causing the motor to knock.

48 The Automobile Randhooh

When to Ketard the Ignition. Always r<^-
retard the ignition before starting the motor,
and take great care that the ignition is retarded
and not by mistake advailced. Some cars are
fitted with a device which prevents the starting
crank being turned unless the spark is retarded.
If it is not clear as to which way to move the
ignition lever to retard th6 ignition, move the
commutator in the slame direction as the cain-
shaft rotates.

As soon as the motor slows a little when go-
ing uphill, retarding the spark enables more
power to be obtained from the motor at the
slow speed, that is to say, if the spark is not
retarded the motor will go slower than if it is
retarded. Do not retard the lever to the utmost
under these conditions; on the contrary, retard
the lever to such a point that the knocking (due
to the wrong position) ceases.

Eetarding the spark causes the maximum
pressure of the explosion to occur at the best
part of the stroke, or, rather, the mean pressure
of the explosion stroke will be lower if the best
point of ignition by retarding is not found. This
is' a matter of some skill and practice.

To slow the motor, cut off as much mixture
as the throttle allows, then slow the motor still
further by retarding the spark, but on no ac-
count retard the spark when the throttle is full
open (for the purpose of slowing the motor),
as the motor will merely discharge a quantity
of flame at a white heat over the stem of the

The Automobile Handbooh 49

exhaust valve, burning it, softening it, and
making it scale.

When TO Advance the Ignition. With too-
early ignition the pressure upon the piston be-
comes excessive and without any= adequate re-
turn of useful work or energy. If the ignition
be retarded too much, the maximum explosive
pressure Occurs too late during the working
or power stroke of the piston, and the combus-
tion of the gases is not complete when the ex-
haust-valve opens. Greater motor speed re-
quires an early ignition of the charge, but
greater power calls for late or retarded igni-
tion.

The reason for advancing the spark when
fast running is required, is that the explosion
or ignition of the charge is not instantaneous
as may be supposed, but requires a brief inter-
val of time for its completion.

It may be well to explain without entering
into theoretical details, that when a motor is
running at normal speed, the ignition-device is
so set that ignition takes place before the pis-
ton reaches the end of its stroke. The later
the ignition takes place the slower the speed
of the motor and consequently the less power it
will develop. If, however, in starting the mo-
tor the ignition-device were set to operate be-
fore the piston reached the end of its stroke,
backfiring would occur, resulting in a reversal
of the operation of the motor and possibly in
injury to the operator.

50 The Automobile Handbooh

Car Inspection. Most autoists are content to
make all their inspection of the car and its mech-
anism from above, and rarely give more than a
casual glance below the frame except when
trouble occurs. On cars fitted with pressure-feed
on the gasoline, the piping should be frequently
inspected, on account of the danger from fuel
leakage. Such inspections should be made
when the motor is stopped, and the pressure still
turned on. The tank should be gone over for
leaks arising through the opening of its seams
from vibration, or the loosening of the union
connecting the fuel lead with the tank. The
lead and its connection to the carbureter should
also be examined for leaks and abrasions due to
rubbing against other parts of the mechanism.
If any such are found they should be immedi-
diately repaired. Twine, tire tape, or rubber
bands will act satisfactorily as fenders to pre-
vent further mischief. Unions which cannot be
made tight by screwing up should be taken
apart and the male connections coated with
soap or red lead, which will render them tight
for a considerable time.

After going over the fuel system, the brake
rods and steering connections should be exam-
ined for loose joints and broken oil and grease
cups. Grease boots on the drive-shaft joints
should be seen to be sound, and filled with
grease. A cleaning out of the dirt from the in-
terior of tlie mud-pan will often reveal lost cot-
ter i)ins or nuts, and tend to a more agreeable
handling of the draincocks, carbureter and fil-

The Automobile Handbook 51

^ter. This time will be well spent when the
chances of fire or accidents arising from faulty
steering or brake connections are taken into
account.

Dont's. In the first place don't forget to as-
certain the fact that the ignition mechanism is
retarded before cranking the motor. Many a
sprained wrist and a few cases, of broken
heads or arms have been caused by the neglect
of this simple precaution. It is a good plan to
have the ignition-control spring so actuated that
in its normal position it is always retarded.

Don't use the electric starting motor to pro-
pel the car. It ruins the battery.

Don't use a match or a small torch to inspect
the carburetor. It sometimes leads to unex-
pected results.

Don't forget to fill the gasoline tank before
starting.

Don't smoke while filling the gasoline tank.

Don't take out all the spark plugs when
there is nothing the matter, except that there
is no gasoline in the tank.

Don't forget to always have an extra spark
plug on the car.

Don't allow the motor to race or run fast
when out of gear. If the car is to be stopped
for a few minutes, without stopping the motor,
retard the ignition and also throttle the charge,
so that the motor will run as slowly as possible.

Don't fill the gasoline tank too full, leave an

52 The Automobile Handbook

air space at the top or the gasoline will not flow
readily.

Don't have any open hole in the gasoline
tank. When the car is washed water may run
in this hole, mix with the gasoline and cause
trouble.

Don't put grease in the crank case of the
motor, it will clog up the oil holes and prevent
the oil from circulating.

Don't fill the gasoline tank hy lamp or candle
light, something unexpected may happen.

Don't keep on running when an unusual noise
is heard about the car, stop and find out what
it is.

Don't start or stop too suddenly, something
may break.

Don't pour gasoline over the hands and then
rub them together. That rubs the dirt into the
skin. The proper way to do is to saturate a
towel with gasoline and then wipe the dirt oflf.

Don't forget to examine the steering gear
frequently.

Don't fail to examine the pipe between the
carbureter and the admission-valve occasionallv.
The pipe connections sometimes get loose and
allow air to enter and weaken the mixture.

Don't forget to see that there 13 plenty of
water and gasoline in the tanks.

Don't fail to clean the motor and all the
wearing parts of the car occasionally.

Don't forget to oil every part of the motor

The Automobile Handbook

where there is any friction, except the valve
stems/

Don't forget to put distilled water in the bat-
tery every ten to fifteen days.

Automobile Tools. In Fig. 7 three types
of valve lifters are shown. B and G are of the
same principle, and quite efficient in almost any
case; but A, when properly operated, and on
its respective motor, is. more quickly applied,

Fig. 7

and consequently a time saver. D is a valve-
seating tool, supplied as special equipment by
one of the large motor car manufacturers.
In Fig. 8 are shown a couple of spanner

wrenches and one or two other tools that are
quite uncommon but quite necessary in the work
to which they are adapted. A is made from a
piece of steel tubing and used on packing
glands — the tube to slip over the shaft — and the
small lugs at the end engage corresponding

The Automobile Handbook

recesses in a. packing nut. B is represental
of a valve-grinder, designed especially for
valves in certain motors. The spanner C is
quired to conveniently remove certain types
cylinder plugs; while D, which approaches
conventional, is used in adjusting bearings
a particular type.

There is probably a greater variety of wi
and gear pullers now in service' than of i

other special tool. In Pig. 0, A looks vi
much like the standard adjustable wheel t
gear puller for sale in all supply houses ; t
it practically is the same except that the hoi
are larger and twisted in opposite direeti.
and at right angles to the beam. It is foi
useful in removing road and flywheels and
like. B is a non-adjustable tool made especia
for removing flywheels. C and P are road wh
pullers, and are included in the regular equ

The Automobile Handbooh

ment of tools supplied with the cars of two
prominent manufacturers. C is part of the
Rambler tool equipment and is used in connec-
tion with their spare wheel; and P represents
the type of wheel puller supplied by the Pierce-
Arrow. E is a gear-puller designed to remove
the half-time-gears of an Oldsmobile, the two

Fig. 9

side-screws being intended to fit into threaded
holes in the web of the gears.

When the Jack is Missing. Should the jack
be missing or broken, an efiScient substitute can
be rigged from a large stone or a number of
bricks piled one on another until the height is
sufficient to lift the wheel from the ground.

5G The Automobile Handbook

Having gotten the stone or piled the bricks obi
of the floor-boards can be utilized as an inelino
plane and the ear backed up until the axle rest
on the top of the pile. "When the work has bee
IX'tfornied, the axle will have to be pushed o:
the pile, bnt as the drop is inconsiderable n
liarm can come to the tire. Where staUe-aiv

rider fences abound, one of the rider timbei
can be utilized as a lever, with a stone as a fu
cnim to raise the axle, supporting the latti
with another stone during the repair, and genti
easing down the axle when ready to proceed.
Removing Dents, An easy method of remo'
ing dents consists of soldering a piece of wii
to the bottom of the dent, then pulling the d

The Automobile HandbooJc 57

^iressed portion out to its proper position. When
the dent happens to be in an oil, or gasoline
tank, or a radiator, an old valve can be most
effectively used in place of the wire, as shown
in Fig. 10 The top surface of the valve is filed
smooth and bright, then cleaned with soldering
acid and tinned with solder. A flat surface of
the same area, and as near the bottom of the
dent as possible, is treated in the same manner,
and the valve sweated on. This sweating on is
done by placing the prepared portion of the
valve against the tinned surface of the dent,
and then applying heat with a torch till a f u-
>ion of the solder takes place. The heat should
then be removed and the solder allowed to set.
When cool, it will be found that with the valve
item as a handle and lever, and probably a few
light taps with a hammer around the edge of
the dent, the deformed part can be most easily
straightened out.

Tools Necessary. The following tools should
be in the car when on the road:
Monkey wrench, 9 inch.
Machinist 's screwdriver.
Ball pene hammer, one pound.
Combination pliers, 8 inch.
Set of double end, or **S'' wrenches.
Flat file, mill cut.
Three cornered file.
Round file, six inch.
Center punch.
Prick punch.

58 The Automobile Handbook

Drift punch, flat ended.

Offset, or ** bent-end" screwdriver.

Cold chisel, three-quarter inch.

Spark plug wrench.

Small wire cutting pliers.

Emery cloth.

Cotter pin puller.

Wire brush for spark plugs.

Break Downs, ajid Their Kemedies.

Chaiist Broken". In case a chain should break,
and there are no spare links available, the car
may be driven by the other qhain, provided the
idle sprocket is secured so "that it cannot re-
volve. An easy way to do this is as follows:
Pass one end of the chain around the sprocket,
secure the end link to the chain with wire, and
attach the other end of the chain to some part
of the car, as a running board bracket.

On shaft driven cars the universal joint pins
sometimes work loose, and drop out. In such
cases a temporary pin can be made from a bunch
of wire, or by a "mall chisel held in place by
wires, or twine.

CiRCULATixG Pump Leakage. Leakage of
the water circulating pump occurs usually
where the cover joins the pump body by means
of a ground joint. A gasket of stiff paper
(lipped in lubricating cil inserted between the
cover and the body will remedy this, the gasket
being easily formed with the pocket knife. As-
bestos cord is better than paper when treated
with vaseline and graphite, but few autoists

The Automobile Handbook 59

carry it. For leakage around the pump spindle
the cord can be used, pushing it in with a piece
of strip brass or other soft metal so as to avoid
-scratching the shaft. If no asbestos cord is at
iand one of the strands of a piece of hemp rope
"treated with tallow will also answer.

Cranking with Safety. The principle in-
"volved in safely cranking an engine is, to get
-the explosion at the moment the crank is pull-
±ag on the fingers, so that if the kick comes the
force will simply pull the handle out of the
^rasp, instead of being expended against the
l)ody weight and applied force. Do not attempt
to turn the crank all the way around ; adjust it
to start against the compression, then give a
quick pull upward.

Differential Casing. In cases of emergency
where oil or grease cannot be obtained for fill-
. ing the differential casing, beeswax may be
used as a substitute.

Dry Cells for Ignition. Dry cells will give
very satisfactory ignition for a four cylinder
motor by using four sets of four cells each, con-
nected in series multiple so as to get a voltage
of only six volts. By having the vibration re-
spond quickly to the pull of the magnet in the
coil, battery consumption will be greatly les-
sened. The slightest current should separate
the contact points.

Gasoline Pipe Broken. When the gasoline
pipe breaks, a short piece of rubber tubing
forced over the broken ends will do for a short

60 The Automobile Handbook

time, but as gasoline attacks the rubber, too
much dependence should not be put on it, and
the pipe should be brazed at the nearest shop.
If the hole is only a small one a piece of soap
squeezed in and held in place by a soaped rag
and string will serve if gravity feed is use'!I.
For pressure tanks a piece of rubber tubing
split lengthwise and well soaped will tempora-

rily stop the hole, if wired tightly around the
pipe, but the pressure must be kept low, other-
wise the rubber tubing will be loosened and the
leaking commence again.

A leak is sometimes hard to locate, but if the
pipe is rubbed with soap suds, and then blown
through, the leak will be located by the bubbles.

Gear Teeth Broken. If several teeth are

The Automobile Handbook 61

wrholly, or partly broken they may be repaired
in the following manner; referring to Fig. 11 :
Shape out a dovetail recess across the face of
the wheel, cast or shape up a brass, bronze, or
steel segment and dovetail it in, driving it tight
Erom one side, and securing it with screws.
Then file the teeth to a template made from the
standing teeth of the wheel. For a single tooth
proceed in the same way, no screws being neces-
sary if properly fitted and the ends peened over
with a hammer; or, file down the broken tooth
lush with the bottom, drill and tap two or
:hree holes, according to the width of the wheel,
jcrew in capscrews and trim with a file. It
night be well to add, wfeen removing a timing
^ear for repairs, or ^ny other purpiose, care
;hould be taken to see that it, and the gears
with which it meshes, are plainly marked.

Miss Fire Cylinder. Should one of the cyl-
inders miss some of its regular explosions at
intervals when under a load, it may be located
by stopping the engine, and touching each cyl-
inder with the business end of an unlighted
match. The cylinders that have been doing
their regular work will be hot enough to ignite
the match, while the missing cylinder will not.

Nuts and Screws — ^How to Loosen. Eefrac-
tory nuts may be loosened by heating, by means
of a red-hot piece of iron held on or near them
for a few minutes. This will expand the nuts
and they will then come off readily. When a
screw cannot be readily loosened with a screw-

The Automobile Handbook

driver, the latter should be pressed hard into
the slot, while a helper applies a monkey wrench
to the flat part of the blade. A tight radiator
cap can be moved by winding a quantity of
twine, or cloth tightly around it.

Priming. If a motor does not start readily,
due to not getting a rich enough mixture at
slow speed of cranking, tie a small bunch of
waste with a wire close to the air intake of the

Fig. 12

Section of Radiator Showing Washers Held by Wires on

Stick, To Stop Leak

carbureter, then prime by saturating the waste
with gasoline. The added vapor will make
starting easy.

Radiator Leaking. In case a ** honeycomb'*
radiator starts leaking at the end of a cell, and
there is no radiator plug at hand, a substitute
may be made by passing a long bolt of small
diameter through the defective cell and fitting
each end of the bolt with washers made of
leather, or rubber backed with iron washers or

The Automobile Handbook

metal strips, and then screwing down the imt
until the leak is stopped. If a bolt cannot be
oi3tained a small piece of wood may be whittled
down to take its place, and the washers secured
by means of copper wire as shown in Fig. 12,

lll.i
III

Ijllll

If a leak occurs inside one of the cells, a sr|«are
peg cut from soft wood, and covered with a
piece of thin cloth smeared with white lead can
be used as a plug. Only a moderate force
should be used in these methods, as the tubes

The Automobile Handbook

are easily buckled. Leaks in gilled radial
may be stopped by applying a rubber patch I
in place by tire-tape and wire.

Bods or Links Broken. The repair o
broken link in the steering gear can be effec
by placing the broken ends together and fasi

Fig. 14

Valve Spring Strengthened by Inserting Metal St

ing a rod or a piece of gaspipe against the li
winding the wire the entire length of the r
If two hand vises can be obtained they can
attached as shown in Fig. 13. The rod is t
to the joined ends of the link with wire, and
hand vises screwed down on both link and r
Anything but slow running with either of th

The Aulomoiile Handbook

repairs is out of the question. Any other rod
aan be similarly repaired provided there is room
Cor the pipe or the vises alongside of it. Wire
sable can be substituted for brake rods, but the
brake must be kept clear of the drum by some
oaeans when not in use.

Squeakino Springs. A frequent source of an-
aoyance is the squeaking caused by the leaves of
;he springs having become dry from want of lu-
arieation. When such is the case, jack up the

car until the wheels are clear of the ground,
and the springs quite free. Then with a thin
cold chisel, or a large screwdriver, gently force
the leaves apart, one by one, and spread a mix-
ture of vaseline, oil and graphite between them,
using an old table knife or thin wooden paddle
for the purpose. Where parts cannot be
reached in this way, oil should be squirted in,
and if necessary the leaf clips may be removed
to allow of this being done.

Tbembler Blades Broken. Corset steels may

The Automobile Handbook

be used as blades for trembler coils, by cutting
them to the proper length, and riveting the
platinum button from the broken blade through
the hole which is punched near the end. After
making the holes for the retaining screw, the
blade is complete. A piece of the main spring
of a clock will also make a good blade.

TwmB Is Useful in Breakdowns. Autoists
should always carry 15 or ^ yards of strong

twine in their kit, as it may be put to various
uses about the car, such as reinforcing weak
spots in tires, protecting chafed wires, and bind-
ing together split sections of the steering wheel.
Twine may also be used as a substitute in the
absence of a lock washer, by forming a loop
slightly larger than the diameter of :the nut,
and then wrapping twine around this loop,
forming a "grommet," as sailors call it When

The Automobile Handbook

the But is screwed down upon the grommet it
will be held as firmly aa if fitted with a nnt-
lock, and will stay tight until the twine rots.

Axles, Defijutions of. The following defini-
tions apply to the forms of rear axles that are
now and have been in use on shaft-drive cars.

A "live axle" (no longer used) is one in
which the driving member is carried by a bear-
ing at each end, the outer end carries the wheel
and the inner end the differential.

Fig. 17
Semi-Floating Rear Axle

A "semi-floating axle," Fig. 17, is one in
which the driving member is carried on one
bearing at its outer end and with the inner end
supported by the differential. The outer end
carries the wheel.

A "three-quarter floating axle," Pig. 18, is
one in which the driving member is carried by
the differential at its inner end and at the outer

68 The Automobile Handbook

end is carried by the hub flange, the flange
being bolted to the wheel. The wheel is
carried by a bearing that runs on the oatsi
the end of the axle housing tube.

A ' ' full floating axle, ' ' Fig. 19, is one in ■«
the driving member is carried by the difliere
at it£ inner end and at the outer end is cai
by a jaw clutch, the clutch itself being eng

The Automobile SandhooJc 69

'^with and meshing with the wheel hub. The
'wheel is then carried on two bearings that run
~ €m the outside of the axle housing tube. With

Fig. 19

Full-Vloatlng Rear Axle With Annular Ball

Bearings

this constmction, the drive shaft may be entirely

withdrawn from the car without disturbing the

wheel or other axle parts.

The Automobile Handbook

Axle, Front. So far it has not been found
practical to combine the tractive and steering
functions of an Automobile in one set of wheels
and axle. Therefore it is necessary to use a
rigid front axle with knuckle jointed spindles,
for steering purposes, and utilize the tractive
power of the. rear wheels only to propel the
car. Some of the earlier forms of steering
axles had the wheel pivots inclined so as to
bring the projection of the pivot axis in line
with the point of contact of the wheel with the
ground, but as such constructions have not
proved satisfactory they have in most cases
been abandoned.

Fig. 20

■The Aut&mobUe Handbook

Front Axles. Figures 20 and 21 show four
yles of front axles with steering-pivot ends :
shows a solid axle of square section, with
te Hteering-pivot jaws and axle proper, of a
ngle fbrging — B represents an axle of tubular
■oss-seetion with the steering-pivot jaws boreil

■RONT AXLES

Fig. 21

it to receive the tubular axle which is firmly
■azed therein — C shows another style of tubu-
r axle, in which the steering-pivot jaw ends
e turned down to fit the inside diameter of
e tube and are also brazed in position, while
illustrates a one-piece axle with vertical hubs

The Automobile Handbook

Fijr. 22

The AutomdbUe Handbook

Tin. 23

TkeAutonwbile Handbook

The Automobile Handbook 75

instead of jaws, which carry L-shaped steering-
pivots, instead of the usual form of knuckles.

Steering Knuckles. In order to obtain ease
>f operation and secure the shortest turning
radius with the lejast movement of the steering
?v^heel or lever, the knuckle of the steering pivot
jhould be as close to the center of the wheel
IS is possible. It is also cf great importance
;hat the steering knuckles should be as heavy
IS is practically consistent with the size and
veight of the car for which they are intended,
'f this imporant point be neglected, rapid wear
md probable fracture of the knuckles may be
ooked for.

A steering knuckle with a spindle and pivot
)f T shape is shown in Figure 22. The spindle
md pivot N and the steering arms 0 are usually
L one-piece forging. The steering arms 0 are
connected by means of a suitable distance rod
ind the steering lever P is attached to one of
he pivots N by turning a shoulder upon it and
Dinning and brazing the steering lever and pivot
lub together.

Figure 23 shows a steering knuckle with
jpindle and pivot of L shape. The steering arm
R goes on the lower end of one pivot Q only,
ihe other pivot having the combined steering
irm and ever S on its lower end. The steering
irms being detachable, the device may be oper-
ited from the right or left hand side by simply
exchanging the levers R and S. The steering
lever S has a ball upon its outer end to fit in the

76 The Automobile Handbook

The AutomohUe Handbook 77

ocket on the connecting rod of the steering
lechanism.

Axle, Eear. A live axle is any axle contain-
ig parts which turn the wheels in addition to
arrying weight.

Dbad Axle, A dead axle ia an axle which
arries weight only.

BrvelCnu-

Flg. 26

Two-Speed Rear Axle With Two Bevel Gears and

Two Pinions

Floating Axle. A special type of live axle
n which the shaft that turns the wheels is in-
lependent of the axle proper, and may be re-
noved without affecting the axle's weight car-
ying capacity.

In Pig. 24, K and L show respectively a
ive solid raar axle and a rigid tubular axle,

The Automobile Handbook

equipped with roller-bearings. The spring
form part of the roller-bearing boxes of the
axle, while they are usually brazed to the 1
lar axle near its outer ends.

A rigid tubular axle with ball-bearing
driving shaft is illustrated in Figure 27, the
cup or race is adjustable by means of a 1
gon upon its outer extension in the rear o
hub of the wheel and is held securely in pog

) /

BALL BEARING AXLE

Fig. 27

and prevented from turning by means of
clamping device shown on the upper portic
the bearing. No separate adjustments foi
inner two sets of ball-bearings are necesj
as the teeth of the spur gears of the differe
which are keyed to the inner ends of the div
driving shaft, being free to slide upon t
selves, allow the shafts M to have a flight L
tudinal movement within the axle tube.

The Automobile Handbook 79

taking up the wear of each pair of ball-bearings
with a single adjusting mechanism.

In any style of full-floating axle the en-
tire weight of the rear end of the car is car-
ried on the axle housing, or casing, leaving the
drive-shafts in the axle with no other work than
that of revolving the wheels. In this axle, by
the removal of the hub caps, the drive-shaft in
each half of the axle can be pulled out, owing
to its being free in the housing, and having gen-
erally a squared end which fits into the bevel
gears of the differential. In a semi-floating rear
axle the complete car weight at the rear is car;
ried on the axle housing, identically as in the
floating axle, but th^ drive-shafts of the axle
are not removable by pulling endwise through
the hub. This is because these shafts are tightly
keyed at their inner ends with differentials,
bevels or, as is the case in one or two cars, the
bevel gear is formed integrally with the shaft.

The newest type of floating axle is that known
as ** three-quarter floating." As will be seen
from the definition on a preceding page, this
form combines several^f the advantages of both
of the other types, while, of course, having cer-
tain disadvantages of its own.

The construction used in Fig. 28 s'hows a
full-floating type of live rear axle in which' the
bearings are of the annular type, and the driv-
ing jaws at the ends of the shafts engage with
the hub in a proper manner to abort failure
from lost motion.

The Automobile Handbook

In this ease the tube is reduced in di&me]
to take the bearings, and the shoulder
formed is taken advantage of in the process
providing for thrust. The shaft has no work
do excepting to take torsional moments, a:

the design throughout includes drop forgin
of steel and drawn-steel parts. The inner ra
of the ball bearings is a sufficiently heavy tul
but it is not shaped in such a way as to act a*
"preventer bearing," hence complete depen
ence is placed on the ball bearings and they a

The Automobile Handbook 81

made large enough to take the responsibility.

Axle, Heab, Thbee-Quarters Floating. In ^
this design, Fig. 18, the axle housing is ex-
tended outward to a point in line with the out-
side surface of the wheel, and the outer end is
made of a diameter just large enough to allow
the axle shaft to pass through it. Mounted on
the outer end of the axle and directly in the
center of the wheel is a single bearing, usually
of the annular ball type. The wheel spokes are
mounted in the hub flange in the usual manner
and the flange is carried upon the outer surface
of the bearing mentioned above. A large hub
forging is bolted to the wheel flange and the
bolts pass through the spokes which hold the
brake drum on the inside. The outer end of
the driving shaft is fastened into this hub forg-
ing by a key way and taper; the inner end of
the driving shaft is carried by the differential
in the same manner as with a full floating type.
It will therefore be seen that the radial load of
the wheel is carried on the single bearing at
the end of the housing, and this bearing is also
required to carry the end thrust. The binding
strains that are imposed upon the wheel when
turning corners, for instance, are provided for
through the rigidity of the driving shaft, which
is fastened solidly into the wheel hub at its
outer end and which is carried by the differen-
tial at its inner end. This gives a leverage equal
in length to the distance between the outer bear-
ing and point of support in the differential.

The Automobile Handbook

The Automobile Handbook 83

Backfiring, Causes of. This is a term applied
to an explosion or impulse which forces the
flywheel of a motor suddenly backwards, that
is, in the opposite direction to its proper rota-
tion. The term is sometimes used in connection
with explosions which occur in the muffler from
the ignition of an accumulation of linburned
gases.

When a back kick occurs and the crank-shaft
rotates in the reverse direction, that rotation
must first be stopped and a rotation started in
the correct direction. To stop the back kick or
reverse rotation requires power, and to again
start the correct rotation calls for power. The
forces that stop the back kick are, the arm of
the person cranking the weight of the rotating
flywheel, and forcing one of the other pistons
to compress the mixture. The force that starts
the flywheel in the correct direction is the ex-
ploding charge of gas in cylinder No. 2 as
illustrated in Fig. 29, in which the piston in
No. 1 cylinder has not reached the top dead
center on the compression stroke when the
spark occurs and the reverse movement of th?
crankshaft starts. In tracing out what happcEs
the valve locations must be considered. Both
Valves — intake and exhaust — in No. 1 cylinder
are closed on the compression stroke and they
will remain closed on the back kick stroke.
Had the motor been running, No. 2 cylinder
would have been going down on the explosion

84 The Automobile Hcrndbook

stroke of the piston, but as there was no previ-
ous explosion, the motor having been idle, the
cylinder would biB filled with mixture, with
both valves closed, as they always are on the
explosion stroke. The piston in this cylinder
was normally going down; but, as soon as the
back-fire occurred, the piston would start up
and the valves remaining closed, the mixture
would be compressed. This pressure would help
to stop the back kick, and as soon as the power
of back-kick was over the compression would
start the piston down on the proper explosion
stroke, which would prove of sufficient power
to carry the motor past the firing point in the
other cylinders. Cylinders 3 and 4 would not
be factors at all, in that the piston in No. 3
would, when the back-kick occurred, be near
the bottom or end of the suction stroke with the
intake valve open, and when the reverse action
of the piston set in it would start rising, simply
driving the mixture out through the open intake
valve and through the carbureter. Cylinder No.
4 was near the completion of the exhaust stroke
when the back-fire started, and the exhaust
valve was open. During the reverse motion
caused by the back fire, the piston would start
descending, the exhaust valve remaining open,
exhaust gases would be drawn into the cylinder
from the exhaust pipe.

Other causes of back firing are,

( 1 ) A WEAK MIXTURE. Bearing in mind that
the mixture is the fuel of the engine, and that

The Automobile Handbook 85

as in a stove, the character of the fuel influences
its manner of burning, it will be evident that
like poor wood, slaty coal, or other imperfect
fuel, a weak mixture is a slow burner. This is
point number one. Proportionate to the speed
at which it is running, the motor has a certain
sharply defined period of time in which it must
complete each part of its cycle, if it is to operate
satisfactorily. Should the parts of the cycle
lap, or run over into one another, there is bound
to be a hitch of some kind. The use of a very
weak mixture causes just such a hitch by rea-
son of the fact that it continues burning for
some time after the completion of the part of
the cycle during which it is supposed to func-
tion, i. e., the power stroke. In fact, it is still
burning when the inlet valve opens to take in
a fresh charge, and as its burning in the cylin-
der maintains considerable pressure therein, the
latter, on the lift of the inlet valve, escapes
through it and the carbureter with a pop,
exactly similar to that of an unmuffled exhaust
except that it is weaker. The remedy is more
gas or less air, or sometimes both, and to find
out just how much of each is required, start
the motor and very gradually cut down its
gasoline supply at the needle valve of the car-
bureter until the motor begins to miss. Then as
slowly increase the supply until the motor will
run steadily and without missing on the mini-
mum opening of the needle valve. Lock the
latter in place. Then speed the motor up by

86 The Automobile Handbook

opening the throttle and adjust the spring of
the auxiliary intake on the carbureter until the
motor is receiving sufficient air to enable it to
run and develop plenty of power at all speeds.

(2) An overheated combustion chamber,
due to a poor circulation of the cooling water —
causing self-ignition of the charge before the
proper time.

(3) Advancing the ignition point too far
ahead when the motor is running slowly under
a heavy load — flywheel has not sufficient mo-
mentum to force the piston over the dead cen-
ter, against the pressure of the already, ignited
and expanding gases.

(4) The presence op a deposit op carbon
Csoot) or a small projecting surface in the com-
bustion chamber which may become incandes-
cent and cause premature ignition.

Batteries. But two forms of batteries are
used in automobile work, the dry cell and the

storage battery. Both are described in the fol-
lowing pages. A distinction should be noted be-
tween battery and cell. A single unit, complete
in itself and capable of giving a flow of current,
whether of the dry or storage type, is a cell.
The ordinary dry cell gives a voltage of 1^^
while a storage cell gives approximately 2 volts.
When it is desired to secure higher voltages, two
or more cells are used in conjunction with each
other and the set then becomes a battery. A
single cell is not a battery.

The Automobile Handbook 87

Batterieo — Dry. A dry battery of the usual
type coDBiats of a zinc cell which forma the
negative element of the battery.

Pig. 30

Sis Cells Boxed to Make

a Battery

Fig. 31

Section Through

Dry Cell

Dry Batteries are very generally used on
moderate speed and low-priced cars. They are
fflmple in construction, comparatively simple in
operation, and their action is ea-sy to under-
stand. Each cell is composed of three elements :
The carbon, the zinc, and the electrolyte. The
carbon usually takes the form of a round stick
placed in the center of a cylindrical vessel made
of zinc in sheet form. The space between the
carbon and the zinc is filled with the electrolyte.

88 The Automobile Handbook

generally a solution of sal-ammoniac, which is
poured in on crushed coke. The top is closed,
or rather sealed, with pitch to prevent the loss
or evaporation of the liquid. Through this,
project the ends of the carbon and the zinc, these
being formed into binding posts for holding the
wires. As this holding of the wires must be ian
intimate relation, the usual form is a threaded
shank upon which a pair of nuts are mounted.
Between these the wire to be connected . is
crushed or compressed by the moving together
of the nuts.

The two poles or binding posts are called the
positive and the negative, and: are indicated by
the + sign for the former and the — sign for
the latter. Carbon being the positive element,
the + sign attaches to it. Now, the act of con-
necting these terminals together so as to allow
a flow of current allows of two different meth-
ods of procedure, a right and a wrong way, it
is true, but that was not what was meant.

In one respect dry batteries have a decided
advantage over storage batteries for ignition
purposes, from the fact that on account of their
high internal resistance they cannot be so
quickly deteriorated by short circuiting.

On account of this high internal resistance,
dry batteries will not give so large a volume of
current as storage batteries, but a set of dry
batteries may be short circuited for five min-
utes without apparent injury and will recuper-
ate in from twenty to thirty minutes, while a

The Automobile Handbook 89

. storage battery would in all probability be
ruined under the same conditions.

It is often desired to secure a greater voltage
than one cell will give, or else to secure a source
of current that will give a greater time of ser-
vice than can be secured from the single cell. In
either ease, it is customary to combine two or
more cells in certain definite combinations and
connect them with each other in such a way
that the desired voltage or length of life is
realized. It is possible to make such combina-
tions by using either dry or storage cells,
although storage cells are usually boxed after
forming.

lb' Switch ToEnefifwTmn*

Pig. 32
The Ordinary Battery Connection, in Series

Two methods are usually employed, viz. :
series, and multiple, or parallel. To connect
dry batteries in series, the terminals are joined
alternately, that is, the zinc of the first is con-
nected to the carbon of the second, the zinc of
the second to the carbon of the third, etc.

"When so joined, the positive element is left
free at one end, and forms the positive terminal

so The Automobile Handbook

of the group, which is then considered as a unit.
The other free end (the negative) forms the
negative tenninal of the unit, see Fig. 32, which
shows four cells connected in aeries.

Figure 33 shows four cells connected in paral-
lel which means that all of the positive termi-
nals are connected to one common wire, and all
negatives are connected to another wire.

This mode cf wiring up the cells gives a
smaller output for the group. Thus if the in-
dividual batteries have an internal resistance

ToEnguaTrame

Parallel Conncctioiie are Not ch FrtquentI? Used
which is low in comparison with the external
resistance^ the total output will be but slightly
more than that of a single cell. If, on the other
band, the internal resistance is high relative tc
the external, the current v.'ill be roughly pro-
portional to the number of cells.

Where the cells are divided into sets or groups
of a small number (four is usual) , and more than
one of these sets are used at a time, there are
again two methods of joining them. These two
are the same as before, viz., series and multiple.

The Automobile Handbook

The former is very seldom used, if ever, but the
other is rather common. When two or more
sets of batteries, themselves connected in series
are, as sets, joined in multiple the whole is
spoken of aa connected in series-multiple.

'foWtch. ToEng-Rumell

Fig. 34

Batteries — Storage. A storage battery as
used in ignition service, is usually of the lead-
aeid type, in which the electrolyte is sulphuric
acid and water of a density about 1.2 — specific
gravity. The plates are oE two classes— posi-
tives and negatives — there being one more nega-
tive than positive in each nesting in a ceil.
The elements of a cell of storage battery are

The Automobile Handbook

given In Fig, 35, and consist of the following:
Positive plates A, of which there is one fewer
than of negatives ; negative plates B, of which
there is always one more than positives; sepa-

Fijr. 35
Kl.'m.'iiis nt As-^ctiiblfil H.iUpry

rators C, whifh may he of wood, rubber, oi
other Ruitahlo material, and if of wood must be
trented ; positive strap D. the function of which
is lo connect all the positive plates, across the

The Automobile Hcmdbook 93

•top, into electrical relation; negative strap E,
the function of which is to connect all the nega-
tive plates, at the top, in electrical relation ; bat-
tery jar F, made of rubber composition, light,
strong and acid proof; cover for the jar G, with
holes for the terminals of the elements, and a
vent ; assembled cell of battery H, showing the
elements in place, separated, with cover on;
ready for connections ; and a battery box I, of
oak, usually contrived to hold three cells of
battery, sometimes two.

The positive and negative plates, called ele-
ments, consist essentially of a grid in each case,
made of lead-alloy, in which antimony is used
to engender stiffness. The grids are in divers
forms, depending upon the views of several
makers, the idea being to afford space for the
active material, and to lock the same in, so that
it will not drift out, as it is prone to do, under
the action of the charging, and discharging cur-
rent. Surface is the great requisite, and it is
the aim to afford the maximum area of the fin-
ished plates, per pound of active material used ;
limiting the weight of the supporting grid, in
so far as it is possible to do so.

The voltage of a battery of this type is usu-
ally 2.2 volts when the circuit is closed, but it
drops to 2 volts within the first hour of using,
which pressure it usually maintains during the
next 5 hours, after which the voltage declines
at a rapid rate.

Adding Water to Cells. In service water

94 The Automobile Handbook

will have to be added to the cells to compensate
for evaporation, and for the loss that takes place
during charge, brought about by the entraining
of water with the bubbles of gas that shoot off
and out of the jars, if they are open, that is to
say, if the covers are removed before and left
off during charging, which is not usually the
case. The result in any event is in favor of in-
creasing strength of the electrolyte, and water
will have to be added from time to time in order
that the plates may not be exposed to the atmos-
phere above the line of active material; which
is a point that must be cared for if the battery
is to last for a long time. The water so added
should be pure — distilled — and the right quan-
tity to add, will be determined by means of a
hydrometer placed in each cell between the sepa-
rators if there is sufficient room, or the electro-
lyte may be withdrawn, through the utility of a
gun made of hard rubber with a long slender
neck. The test should be made when the bat-
tery is charged and every cell should be exam-
ined rather than to test one cell and conclude
that all are in an average condition.

Storage Batteries — Care op. Among the
troubles that ultimately attend batteries in serv-
ice the following are the most conspicuous :

Hardening of negative elements ; local action ;
buckling of plates ; shedding of active material ;
snlphation; reversal of negative elements; dis-
integration of grids; protruding active mate*
rial ', deformation of separators ; broken jars ; in-

^ The Automobile Haiidbook 95

dpient short circuits; defective electrical con-
tact : loss of capacity ; loss of voltage ; corrosion
)f plates, and needle formations.

Hardening of the negative elements will fol-
ow if they are exposed to air, as when the elec-
xolyte is allowed to fall below the level of the
elates, from any process that will produce over-
oxidization if the temperature is allowed to in-
crease much above 90 degrees Fahrenheit,
^hen the negative elements are hard, to reduce
;hem back to the normal condition, assuming
:he prouess is not too far gone: Remove the
dements from the jar, place the negatives in a
jell, with dummy positives, and charge until
he negatives are corrected, taking care not to
charge at a too high rate. High temperature
md excess boiling should be avoided. If the
legatives are charged in their own cell with
ihe regular positives the positives will be dam-
iged by the excess charging that will be neces-
lary to reduce the negatives. When the nega-
ives are sufficiently charged to correct the evil
hey may be returned to their own cell, and
vhen connected up with the positives the cell
vill be ready to go into service again, if in the
neantime the positives are given such attention
IS their condition would seem to indicate. Local
Lction, following impurities in the electrolyte,
vill only be prevented as much as it is possible
o do so when the electrolyte is removed and
)ure electrolyte substituted in its stead. This
ihould be done when the cells are fully charged

96 The Automobile Hcmdbook

The electrolyte will hold most of the impurities
when the battery is in the fully charged state.

Buckling of plates, when batteries are defec-
tive in design, rather than in cells of normal
characteristics, is a trouble that will follow in
any cell if the discharge is allowed to extend
below 1.8 volt as indicated by the cadmium test,
rather than by the usual potential difference
reading across the two sets of elements in the
cell. If the rate of discharge is excessive, a
condition that is not likely in ignition work,
buckling will follow also. Short-circuiting the
elements to see if the battery is alive will tend
to buckle the plates, due to the heavy discharge,
and the uneven rate of discharge over the sur-
faces of the elements. In defective construction,
if the active material is not of the same porosity,
thickness, and in the same condition all over the
surfaces of the plates, buckling will follow.

Shedding of the active material, to a slight
extent, is a normal condition of batteries; and
to prevent trouble due to incipient short cir-
cuits, such shedding is cared for by having a
space in the bottom of cells to hold such
shedded material. When elements are of in-
ferior design and improperly constructed the
active material will shed at a rapid rate, and
the user of the battery can do nothing more than
demand a new battery to replace the defective
one. If charfring is done at a too rapid rate
the active material will be loosened by the raj)-
idly escaping gas, and even on discharge, if the

The Automobile Handbook 97

is high, the shedding of active material is
y to follow.

ilphation, which is a normal expectation
ng discharge of a battery, introduces serious
plications under certain conditions as when
active material is not in intimate contact
1 the grids thus allowing the electrolyte to
between the grids and the active material,
h the result that sulphate, which is a high
stance material, isolates the grids and re-
tes the efficiency of the cell in two ways;
t, by increasing the ohmic losses, and, second,
lowering the chemical activity. Excess sui-
te is prone to form when the electrolyte is

of l)alance, and one of the best ways to
rt this action is to keep the electrolyte with-
he prescribed limits of strength. If sulphate
llowed to form until white crystals show over
surfaces of the plates, it is highly improb-
i that the cells will ever be of sufficient serv-
to warrant continuing them in service. Xhe
r way to afford relief lies in reducing the
wth of sulphate by continuous charging the
: elements in a cell with dummies until the
>hate is reduced. A slow rate for a long
3 may bring about a reform,
egative elements to be reversed must be
w capacity, or the cells must be discharged
:ero and then reversed. In charging it is
iys necessary to make sure that the connec-
s are made in such a way that current will
into the battery, rather than out of it. Volt-

98 The Automobile Handbook

meters in which permanent magnets are used
will serve as polarity indicators, and with them
it is possible to proceed with safety. If a bat-
tery is connected up in reverse when it is put on
charge, instead of being charged it will be dis-
charged, and then charge in reverse. While it
is discharging it will deliver current to the line.

Disintegration of grids will follow if the im-
purities are allowed to enter the electrolyte, as
iron, etc. Continued charging will also have
the effect of reducing the grids to form salts
of lead.

Protruding active material, due to expansion
and displacement of the same, indicates a lack
of binding relation between the grids and the
active materials. There is no remedy. Defor-
mation of separators, when they are made of
rubber compound, follows when the cells are
allowed to heat beyond a certain point. This
trouble will be aborted if the cells are charged
at a normal rate, and if the temperature is not
allowed to increase beyond about 90 degrees
Fahrenheit. When wood separators are used
they will slowly rot and in time it will be neces-
sary to replace them.

Broken jars will allow the electrolyte to leak
out, and frequently the fracture is but a minute
crack, so that it is well to be on the lookout
for just this kind of trouble. If the jars are
properly nested and motion between them is
prevented they will as a rule serve without
breaking.

The Automobile Handbook 99

Incipient short circuits «re likely to go tm-
noticed. They are generally due to detached
particles of active material that lodge between
the plates, especially in vehicle and ignition
types, owing to the short distance separating
the plates, and the use of separators, such as
perforated rubber in the absence of wood, which
have the virtue of being porous but too close to
allow the active material to bridge across the
space between the plates.

Defective electrical contact is due to corrod-
ing of joints that are not made by burning.

Loss of capacity may be traced to such causes
as : If the electrolyte is out of balance or below
the level of the top of the plate ; loss of active
material from the grids; sulphate formed on
the surfaces of the grids, ?solating the active
material ; lack of porosity of the active material ;
impurities and sulphate clogging up the pores
of the active material; low temperature; high
temperature; persistent sulphation, and inter-
cell leakage due to electrolyte spilled over the
surfaces, especially if jars are in actual contact
with each other.

Loss of voltage, as distinguished from loss of
capacity, follows in a battery when one or more
of the cells are dead or below voltage. If one
or more of the cells are reversed they will set up
a counter-electro-motive force, and the over-all
reading of the battery will be reduced accord-
ingly. The remedy is obvious. All the cells

100 The Automobile Handbo/c

should read the same way, and all should ha^'
the same difference of potential, respectively.

In view of the sulphated condition that a1
tends all batteries that are discharged at a loi
rate for a long time, as is the case in ignitio:
work, it is necessary to charge at a low rate fo
a long time in order to reduce the sulphate
which is in persistent form and very difficul
to reduce. It will not be enough to correct th
strength of the electrolyte once during th<
charging process for the reason that it w^ill b
difficult, if not impossible, lo ascertain the eon
dition of the same with any degree of accuracy
and the necessity for noting strength two o
three times in the act of charging is apparent
When the battery is fully charged, which ma;
take even sixty hours of continuous charginj
at a low rate, the electrolyte in every cell shoul(
^itand at full strength, considering a state o
full charge, and the color as well as other indi
cations of a full charge should be fully noted
Boiling at a slow rate should be tolerated fo;
several hours, but the temperature should h
held at about 90 degrees Fahrenheit during th(
entire time. If a battery is charged at frequen
intervals it will last longer in service, give lea
trouble in charging and will be more reliable ii
service. It is well to begin charging directly i
battery is taken out of service as any delaj
after that time will result in a marked deteriora
tion of the cells.

When a car is put out of commission, ever

The Automobile Handbook 101

for a few weeks, the battery should be given a
light discharge, and a subsequent charge as
often as once a week, until it is again brought
back into use.

Storage Batteries — Charging. Positive
plates in the charged state are of a velvety
brown or chocolate color; negative plates have
the color of sponge lead, which is very nearly
light gray. When a battery is approaching a
condition of full charge the color tones up quite
noticeably, and it is possible to mistake a con-
dition of full charge, if color alone is taken as
the evidence ; the exterior will have the appear-
ance of full charge, since the active material,
on the exterior surface, will reach its charged
form first ; if the thickness of active material on
the grids is very thick, as it is likely to be in
low discharge rate work, charging by color,
as evidence of a state of full charge, will be to
limited advantage. Details regarding the
proper care and upkeep of storage batteries are
given in the following pages.

Storage Batteries — Testing. Tests for im-
purities in the electrolyte may be made as fol-
lows. For iron;

Neutralize a quantity of the electrolyte to be
investigated, after diluting the same, by the
addition of an equal amount of pure distilled
water, using strong ammonia water for the pur-
pose. To the solution, so neutralized, add one-
thirtieth of the amount of the same of hydro-
gen peroxide, thus reducing any iron present

102 The Automobile Handbook

to the ferric state. If a sample of this solution
is rendered alkaline by the addition of a suffi-
cient quantity of ammonia water, then, if iron
is present, enough to amount to anything of
great moment, from the battery point of view,
a brownish red precipitate will form. A test
for chlorine is as follows:

Make a solution of nitrate of silver in the
proportion of 20 grams of the same, in 1,000
cubic centimeters of pure distilled water, and
add a few drops of this solution to a small quan-
tity of the electrolyte to be investigated; if
chlorine is present the solution will turn white,
owing to the formation of chloride of silver,
which will precipitate out.

A test for nitrates is as follows : In a test tube,
holding 25 cubic centimeters of electrolyte to be
tested, add 10 grams of ferrous sulphate; to
this carefully add 10 cubic centimeters of chem-
ically-pure sulphuric acid by pouring the same
slowly down the side of the tube; in the pres-
ence of nitric acid, a brown solution will form
between the electrolyte to be tested, and the
concentrated solution of sulphuric acid.

The presence of copi)er may be detected from
the fact that when ammonia solution is added
to electrolyte, a bluish-white precipitate will
form. In testing for mercury, lime water, if it
is added to electrolyte in wliich mercury is pres-
ent will evolve a black precipitate. Testing for
acetic acid is as follows: To a small quantity
of the electrolyte to be tested, add enough am-

The Automobile Handbook 103

monia water to render tlie same neutral ; ferric
chloride added to this solution will cause the
some to turn red in the presence of acetic acid
and the solution will then bleach, provided
hydrochloric acid is added, thus affording con-
■clusive proof of the presence of the undesired
acetic acid.

Pig. 36
Section Through Storage Battery Used For Light-
ing and Engine Starting

Battery, Storajfe, Starting and Lighting
^pea. The foregoing description and instruc-
tions relating to storage batteries apply equally
well to ignition, starting and lighting types.
The following rules include the standard bat-
tery instructions adopted by the Society of
Automobile Engineers for the installation and

104 The Automobile Handbook

care of batteries used in connection with elec-
tric lighting and starting systems.

Batteries must be properly installed. Keep
battery securely fastened in place. Battery
must be accessible to facilitate regular adding
of water to, and occasional testing of, solution.
Battery compartment must be ventilated and
drained, must keep out water, oil and dirt and
must not afford opportunity for anything to be
laid on top of battery. Battery should have
free air space on all sides, should rest on cleats
rather than on a solid bottom, and holding de-
vices should grip case or case handles. A cover,
cleat or bar pressing down on the cells or ter-
minals must not be used.

Keep battery and interior of battery compart-
ment wiped clean and dry. Do not permit an
open flame near the battery. Keep all small
articles, especially of metal, out of and away
from the battery. Keep terminals and connec-
tions coated with vaseline or grease. If solu-
tion has slopped or spilled, wipe off with waste
wet with ammonia.

Pure water must be added to all cells regu-
larly and at sufficiently frequent intervals to
keep the solution at proper height. Add water
until solution is level with inside cover. Never
let solution get below top of plates. Plugs must
be removed to add water, then replaced and
screwed on after filling. The battery should
preferably be inspected and filled with water
once every week in warm weather and once

The Automobile Handbook 105

every two weeks in cold weather. Do not use
acid or electrolyte, only pure water. Do not use
any water known to contain even small quan-
tities of salts of any kind. Distilled water,
melted artificial ice or fresh rain water are
recommended. Use only a clean metallic vessel
for handling or storing water. Add water regu-
larly, although the battery may seem to work all
right without it.

The best way to ascertain the condition of
the battery is to test the specific gravity (den-
sity) of the solution in each cell with a hydrom-
eter. This should be done regularly. A con-
venient time is when adding water, but the
reading should be taken before, -rather than
after, adding water. A reliable specific gravity
test cannot be made after adding water and
before it has been mixed by charging the bat-
tery or running the car.

To take a reading insert the end of the rub-
ber tube in the cell. Squeeze and then slowly
release the rubber bulb, drawing up electrolyte
from the cell until the hydrometer floats. The
reading on the graduated stem of the hydrom-
eter at the point where it emerges from the
solution is the specific gravity of the electro-
lyte. After testing, the electrolyte must always
be returned to the cell from which it was
drawn. The gravity reading is expressed in
"points,** thus the difference between 1.250
and 1.275 is 25 points.

When all cells are in good order, the gravity

106 The Automobile Handbook

will test about the same (within 25 points) in
all. Gravity above 1.200 indicates battery more
than half charged. Gravity below 1.200, but
above 1.150, indicates battery less than half
charged. When the battery is found to be half
discharged, use the lamps sparingly until the
gravity is restored to at least 1.250. If by
using the lamps sparingly, the battery does not
come back to condition, there is trouble in the
wiring or generator system which should be
investigated and remedied immediately. Grav-
ity below 1.150 indicates battery completely
discharged or **run down." A run down bat-
tery is always the result of lack of charge or
waste of current. If, after having been fully
charged, the battery soon runs down again,
there is trouble somewhere in the system which
should be located and corrected. Putting acid
or electrolyte into the cells to bring up specific
gravity can do no good and may do great harm.
Acid or electrolyte should never be put into
the battery except by an experienced battery
man.

Gravity in one cell markedly lower than in
the other, especially if successive readings show
the difference to be increasing, indicates that
the cell is not in good order. If the cell regu-
larly requires more water than the others, thus
lowering the gravity, a leaky jar is indicated.
Even a slow leak will rob a cell of all of its
electrolyte in time and the leaky jar should im-
mediately be replaced with a good one. If there

The Automobile Handbook 107

is no leak and the gravity is, or becomes, 50 to
75 points below that in the other cells, a partial
short circuit or other trouble within the cell is
indicated. A partial short circuit, if neglected,
may seriously injure the battery and should
receive the prompt attention of a good battery
repair man.

A battery charge is complete when, with
charging current flowing at the finish rate
given on the battery plate, all cells are gassing
(bubbling) freely and evenly and the gravity
of all cells has known no further rise during one
hour. The gravity of the solution in cells fuily
charged as above is between 1.275 and 1.300.

If for any reason an extra charge is needed
it may be accomplished by running the engine
idle, or by using direct current from an out-
side source; In charging from an outside source
use direct current only. Limit the current to
the proper rate in amperes by connecting a suit-
able resistance in series with the battery. In-
candescent lamps are convenient for this pur-
pose. Connect the positive battery terminal
(with red post, or marked P or +) to the posi-
tive charging wire and negative to negative.
If reversed, serious injury may result. Test
charging wires for positive and negative with
a voltmeter or by dipping the ends in a glass
of water containing a few drops of electrolyte,
when bubbles will form on the negative wire.
When, charging, start at the starting rate and
continue the charge at this rate until the cells

108 The Automobile Handbook

gas freely. Then continue the charge for six
hours at the finish rate. The specific gravity
at the end of the charge should read between
1.275 and 1.300. If the specific gravity does
not reach this point, continue the charge at the
finish rate until the specific gravity stops ris-
ing, which is an indication that the battery is
fully charged.

A battery which is to stand idle should first
be fully charged. A battery not in active
service may be kept in condition for use by
giving it a freshening charge at least once a
month, but should preferably also be given a
thorough charge after an idle period before it
is replaced in service. Disconnect the leads
from a battery that is not in service, so that it
may not lose charge through any slight leak
in car wiring..

The Automobile Handbook

109

Bearings, Ball. Ball bearings may be broadly
divided into three classes— thrust, cone and an-
nular. Thrust bearings are those intended to
sustain end thrust, and in them care must be
exercised to see that the points of contact of
the balls are exactly opposite, and that the
grooves in which the balls run are formed to a
sectional radius a little larger than that of the
balls, thereby securing safe and easy move-
ment of the balls. These grooves must be de-
signed not only to give smooth rolling contact,
but so that a measurable area of the ball *s sur-
face contacts with the race. It is also possible
for a thrust bearing to act at the same time as
a radial bearing, in which case, however, the
four-point system must be used. In thrust bear-
ings the balls are constantly under pressure and
table 5 gives suitable loads for equal shaft diam-
eters and revolutions for different sizes and
numbers of balls :

TABLE 5.

Shaft

Allowable

Number

Ball

Diameter,

Load

R.P.M.

Diameter

in Inches.

lbs.

Balls

in Inches

2.55

550

500

2.55

1.000

500

2.55

1,200

500

11/16

2.55

1,300

500

2.55

1,600

500

2.55

1,800

500

The adjustable cone bearing. Fig. 39, has been
used in millions of bicycles with excellent re-
sults, but under large loads has been found in-
adequate. A ball can roll freely only with op-
posite points in contact, and every third or

The Automobile Handbook

fourth point of contact involves more or less
spinning, or sliding movement of the ball, which
shortens its life, and the bearing must operate
to the detriment of the contact surfaces.

The third and great type of ball bearing is
the so-called annular one intended for radial
loads. It consists of three elements — two races
and the balls. The new annular bearings re-
quire no adjustment or fitting, and the rolling
action of the balls takes place without interfer-
ence of friction. A wonderful advantage of
this bearing is that as high as 96 per cent of the
space between the races can be filled with balls,
the balls being introduced through filling lots
whose size is a little less than the diameter of
the balls to be introduced, so that the balls are
forced between the two races under pressure
and by virtue of the elasticity of the material.
In tlie annular bearing but 30 per cent of the
balls are under load at one time, and it is pos-
sible for equal axle sizes and speeds to use dif-
ferent dimensions and loading according to
the size of the balls. Table 6 gives suitable
loads for equal shaft diameter, and revolutions
for various sizes, and numbers of balls.

TABLE 6.

Shaft

Allowable

Diam.

load on

inches

Bearing, lbs

,'i.l4

1,000

3.14

1.300

.S.14

2.500

3.14

3,000

3.14

4.500

R. P. M.

No. of

Balls

500

Diam. of

Balls,

Inches

The Automobile Handbook

Annular ball bearings are also made with two
rows of balls, and in the majority of them each
ball is Id a separate cage. Experiments have
proven that, where the balls contact with one
another, after a few years the friction results in
grooves being worn in them. In Fig. 37 is shown
the form of separator used in the F. & S. bear-
ings. If in the application of this bearing it is

necessary to sustain heavy axle loads, it is ab-
solutely necessary to add ar. independent thrust
bearing, or to employ a combination bearing
which takes the place of bolt thrust and radial

Ball Bearings — Two in One. Pigs. 38, 39,
and 40 illustrate a ball bearing manufactured at
Bristol, Conn., which owing to its dual ability aa

112

The AutwnobUe Handbook

&ti expressed by its name ("two in one") la
especially adapted to automobile service. Its
makers claim that it is able to withstand radial
or thrust loads, or any combination of the two,
with the use of but a single bearing with its
attendant simplicity of mounting. In order to
bring about this result, two rows of balls are
employed in staggered relation to one another,
and the ball races are so arranged that the line

of pressure is either at an angle of 45 degrees
or 60 degrees with the horizontal, when the axis
of rotation of the bearing is in a horizontal
plane.

Figure 38 shows the pennnnent assembly of
the bearing, sufficient metal being provided in
the shell to permit of drawing the latter tightly
over the cups.

The Automobile Handbook

113

Figure 39 shows the various parts of this
bearing, and Fig. 40 is a semi-sectional view
showing the order of their assembly, from the
shaft outward, as follows ; the cone, the separa-
tor, the two cups and the shell. It will be no-
ticed that the line of pressure of the cone, eups,

and balls is at an angle of 45 degrees with the
horizontal, and this feature applies equally to
both rows of balls, thus adapting the bearing
to withstand a load from any angle. Two semi-
circular races are turned in the cone to receive
the balls, while the sheet metal separator is so
stamp''d that the ball ret'-ining notches are

114 The Automobile Handbook

staggered with reference to each other. These
openings are made slightly larger than the ball
diameter, so that the contact between the ball
and separator is said to be a point contact at
one end of the axis of rotation^ while the weight
by separator is carried on the balls at the top
of the hearing. By maintaining the relative
positions of the balls at all times, cross friction

it is claimed is entirely eliminated, while the
friction introduced by llie use of the separator
is practically negligible.

Ball Beabings — Lubrication of. Ball bear-
ings must be so housed in as to retain lubricant
and exclude dust, grit, etc. An impression that
ball bearings will operate without lubricant is
quite general. It is barely possible that abso-
'utcly true spheres might roll on absolutely

The Automobile Handbook 115

true surfaces if both were made of materials
that were absolutely inelastic, and therefore
would remain true under load. But since such
absolute perfection of the shape is not to be had,
some means must be taken to provide and re-
tain lubricant.

Bust and acid must be kept out of ball bear-
ings. Experience and most carefully conducted
tests have proven that long life under load can
be realized from ball bearings only when the
surfaces are not only true, but are also highly
polished and smooth. Roughness will be broken
down and leave still greater roughness. Rust
and acid will destroy originally true and smooth
surfaces. Since not a few lubricants contain
free acids, care in their choice must be exercised.
Plentiful lubrication and a properly closed
mounting are safeguards against rust.

In the lubrication of ball bearings it is advis-
able to use vaseline; or, when a lubricant of
greater body or stiffness is desired, to use a mix-
ture of vaseline and some high-grade mineral
grease. The grades known as semi-fluid are very
well suited for this use and any combination
may be used with success in such cases.

Annular Ball Bearings. In the annular ball
bearing, Fig. 42, a race of balls C is contained
between an inner retainer A and an outer race
B, there being grooves in the opposing surfaces
of these to receive the balls. In a Hess-Brisrht

116 Ths Automobile Handbook

bearing of this type, as illustrated in Fig. ^1,
the entire space between the races C and B is
not occupied by balls, but is utilized in different
ways. In this only enough balls to make a half
circle in the bearing are used, and these are
spaced apart by means of small helical springs.
These springs contain oil pads of felt, and are
headed by sheet-metal discs that extend far

Hess -Bright Bearing

enough into the grooves to prevent bidewise dis-
placement of the springs, without, however,
producing any more than a negligible friction.
Assembling this bearing one race is placed ec-
centric to another race and the ref|uisite num-
ber of balls slipped into positions, after which
Ihe races are made concentric nnd the balls reg-
ularly distributed. This done, the s''pnratin'l
springs with lubricating mears pre ins*»]led.

The Automobile Handbook 117

Once the springs are in place the tension of them
is snch as to make the bearing self-contained.

It is not practicable to disassemble or repair
the various forms of annular ball bearings in
the ordinary shop. These forms are not adjust-
able and are not designed to be taken apart.
It is quite possible to raform the races and to
insert new balls when the bearing is badly worn
or scratched, but such work must be done with
machinery and tools especially designed for
handling it. Ball bearing repairs are handled
by various companies who specialize on such
work and it will always be advisable to eom-
mimieate with one of them.

Hard and Soft Bearings. There are two
general classes of solid bearings, those which
contain a large per cent of copper and a small
amount of the softer metals ; which are known

118

The AutomobUe Handbook

as hard metals, as brass or bronze. Those which
contain a large proportion of tin or lead and a
small per cent of copper are known aa soft
metals — as babbitt-metal, anti-friction metal and
white metal.

In some instances and under certain condi-
tions it has been found that a good close-grained
cast iron makes an excellent bearing metal.
Being of a granular nature, it has the property
of retaining the lubricant in place, even when
highly polished and under great pressure, with

Fig. 43 Fiff. 44

Types of Plain Bearings

a low co-efficient of friction, but is too brittle
to withstand severe shocks.

Plain Bearings. Plain solid bearings are
used on many parts of an automobile, particu-
larly in the engine and transmission bearings,
although ball and roller bearings are taking
their place in many constructions. The major-
ity of the ears use brass, bronze or babbitt-metal
on the main and crankshaft bearings, while ball
and roller bearings are used on the transmission
riid wheel bearings. A typical plain bearing is
shown in Fig. 43, in which A is the journal made
of steel, while the bearing members shown at

The Automobile Handbook

119

B. B. are made of either brass, bronze, or babbitt
metal. Figures 44 and 45 show different types
of connecting rod bearings. For plain-bear-
ings, the shafts of which are continuously run-
ning at a high rate of speed, such as motors
and speed-change gears, the working pressure

Fig. 45

Solid Connecting Rod Bearing

per square inch should not exceed 400 pounds.
As the arc of contact or actual bearing surface
of a journal bearing is assumed as one-third of
the circumference of the journal itself, the pres-
sure per square inch upon a bearing is therefore
equal to the total load upon the bearing, divided

120 The Automobile Hcmdbook

by the product of the diameter of the journal
times the length of the bearing.

Let D be the diameter of the journal or shaft
at its bearing, and L the length of the bearing,
if W be the total load or pressure upon the bear-
ing and P the pressure in pounds per square
inch of bearing surface, then

W
P =

DXL

If the total load or pressure on the bearing
be known and the diameter of the shaft given,
then the proper length of the bearing will be

L=: ■•

DXP

If the length of the bearing be known and
other conditions as before given, then the proper
dianif ter of the journal will be

D=:

PXL

The Automobile Handbook 121

Bearing, Boiler. A form of bearing used in
a large Dumber of cars of all types is that
known as the roller. This form is made in three
distinct tj^es, one of which is known as the
taper roller, another one the solid straight
roller, and the third one the flexible roller.

The taper roller bearing, Fig. 46, is composed
of an inner and outer race, the inneT race being

Pig. 46
Taper Roller Bearing

designed to fit over the shaft and the outer one
being carried by the bearing housing. The
outer surface of the inner race is conical in
form and the inner surface of the outer race is
of a form to correspond, that is, its internal
diameter is smaller at one side than at the
other. Between the two races is carried a series
of steel rolls, each one of which is tapered so
that it fits between, and bears along its entire
length on both races. This forms a bearing of
anti-friction qualities similar to the annular
ball, with the exception that the contact be-
tween the rolling members and their supports

122 The Automobile Handbook

The Automobile Handbook 123

is a line rather tlian a point. It is customary
to maintain a predetermined distance between
the separate rolls by providing cages into
■which the rolls fit loosely. It will be seen that
because of the tapered formation it would be
impossible to press the inner race hard enough
to cause it to pass completely through the outer
race with the rolls in place, while in the other
direction the inner race would drop out because
of itfi own weight. This feature allows the
tapered roller bearing to withstand a large
amount of end thrust when this thrust is ap-
plied on one side of the bearing only.

Pig. 47
Straight Solid Roller Bearing

Roller bearings are made of an inner and
outer race with both surfaces of each race truly
cylindrical, Fig. 47, and between these races is
carried a series of straight cylindrical rolls.
With plain rolls in use, the bearing will not
withstand any end thrust because of the fact
that the races and rollers will move freely over

124 The Automobile Handbook

each other in the direction of their axes. When
it is desired to have this type of bearing with-
stand a thrust load, one or both of the races
must be made with either a ridge or a groove
at or near one edge and the rolls must then
have a corresponding ridge or groove to en-
gage the race.

The flexible roller bearing is made by the
Hyatt Roller Bearing Co. and consists of two
races, each of which is tubular or cylindrical
in form, and between these races is carried a
series of rollers, as in other types previoiuly
described, differing in that the rolls are formed
from a piece of comparatively thin flat steel
twisted into a spiral. It is from the springiness
of this form of spiral roller that the bearing
takes its name, ** Flexible."

The Automobile Handbook 125

Bendix Drive. The Bendix driye, Pig. 49,
consists of a solid or hollow shaft having screw
threads on the outside, and a hollow gear hav-
ing screw threads on the inside, so that the
gear screws on the shaft like a nut on a bolt
A circular weight is fastened to the gear, and
is slightly out of balance. A coil spring con-
nects the electric motor shaft and the hollow
screw shaft.

Pig. 49
Starting Motor With Bendix Drive
When the electric motor starts It drives
through the spring and turns the screw shaft.
Because of the weight, the gear is too heavy to
turn with the screw shaft, and because the
gear does not turn it must move along the
screw shaft (just the same as if you turned a
bolt having a nut on it, and kept holding the
nut with your fingers to keep it from turning
so that it would be screwed along the bolt).
After the screw gear has moved along the
screw shaft and engages with the flywheel gear
it then keeps on moving along until it reaches

126 The Automobile Handbook

the stop, at the end of the screw shaft. The
two gears then are fully meshed, and it is obvi-
ous that when the screw gear has reached the
stop it cannot move any farther, and it then
must turn with the screw shaft. At this par-
ticular moment the screw shaft and electric
motor are revolving at a great speed, and this
great blow and the power of the electric motor
are both taken through the coil spring. The
spring keeps coiling until all this power has
been applied to the flywheel gear and the en-
gine starts turning.

As soon as the engine starts exploding and
runs under its own power, the flywheel of
course turns much faster than it was cranked
by the starter. Because it is now turning so
much faster it increases the speed of the screw
gear so that the latter runs faster than the
screw shaft on which it is mounted. It is there-
fore plain that if the screw gear runs faster
than the screw shaft, that it will be screwed
on the threads of the shaft (like a nut on a bolt)
until it has been screwed out of mesh with the
flywheel gear. This demeshing movement is
entirely automatic and eliminates the nse of
an overrunning clutch. And now that the
screw gear is out of mesh it is natural to sup-
pose if the electric motor keeps running that
the gear will be automatically screwed right
back into the mesh with the flywheel gear. But
the unbalanced weight on the screw gear per-

The Automobile Handbook 127

forms its automatic function. That is, being
slightly out of balance, the weight twists or
cocks othe screw gear so that it clutches and
binds on the screw shaft and turns with it. This
automatic clutching is all due to the centrifugal
force of the unbalanced weight.

When the electric motor stops running, the
screw gear has been fully screwed away from
the flywheel gear, and it remains in that re-
tarded position until it is again required to
start the engine.

The screw shaft should never be oiled or
lubricated. It is not necessary and, in fact,
the screw gear works to the best advantage
when the screw shaft is dry.

Through accident or otherwise, should the
flywheel ever be entirely exposed and unpro-
tected, and should the gear tend to stick on
the shaft, it may then be necessary to clean
the screw.

The teeth on the screw gear and flywheel are
chamfered or pointed on only one side to make
the meshing natural and easy. However, should
the teeth meet, end to end, the screw shaft
itself is designed to move automatically back-
wards, against and compress the coil spring.
This gives the screw gear time enough to turn
and enter the flywheel gear. Should sticking
of gears ever occur, they can be released by
throwing in the clutch and* moving the car.
Such trouble would be due to incorrect cham-

128 The Automobile Handbook

fering or inaccurate alignment of the gears.
Also it might be due to the binding of the drive
parts and prevent compressing and proper func-
tioning. Such defects should be corrected.

If v^rhile the engine is running, the electric
motor should be accidentally started, the screw
gear will of course screw over against the turn-
ing flywheel gear. But instead of the clashing
and smashing of gears that might be expected
there is no damage whatsoever, as the gears
simply touch once. This is because the flywheel
gear will speed up the screw gear, and thus
automatically screw it away. The turning screw
gear will then automatically clutch and bind
on the screw shaft, in exactly the same manner
as when it is cranking and has been demeshed
when the engine starts exploding.

Bodies. In the construction of automobile
bodies the sills are made strong, and the super-
work is rendered independent of the actual
structural strains. Wood is generally used in
the framing, although it is sometimes replaced
bv cast aluminum.

"When wood is used for framing, sheet alumi-
/lum, steel and thin layers of wood are em-
ployed. The aluminum is laid on a form and
beaten to the shape required for the paneL The
steel sheets are- die formed, while the wood is
made flexible in order that it may be bent to
its proper shape when fastened to the body. In
order to have the car of light weight, aU body
builders use the lightest materials possible in

The Automobile Handbook 129

the construction of that portion which lies above
the chassii^.

When aluminum is used in the panels and
for facings, care must be exercised to prevent
water from creeping ill' between the metal and
the framing, because water causes an electro-
lytic action on the aluminum plates. To prevent
the oxidation of sheet steel, the plates are either
coated with aluminum or zinc, or they are given
a priming coat of paint on* the inside.

As a general thing, putty is not used in the
construction of bodies, as there are few joints
which require it. In the very best body paint-
ing twenty coats are used before the paint as-
sumes i's proper finish. The first coat, or prim-
iug coat, generally consists of pure white lead
mixed in oil. After that the second priming coat
is given to it, and from then on the number
of coats of rough paint will depend upon the
nature of the surface and the degree of finish.
For a very fine finish, the last coats consist of
varnish, but when wagon finish is desired, the
last coats consist of paint.

Finishers must take into account the fact that
alLcars are more or less abused in service, and
it is to be expected that the magnificently
equipped limousine will have a somewhat finer
finish than the hard used touring car.

Classification op Bodies. Besides being
classified according to the type of gasoline en^
e:ine, methods of transmission, number of cyl-
inders, etc., automobiles are also classified ac-

130 The Automobile Hcmdbook

cording to the type of body which is mounted
on the chassis. While there are a considerable
number of names which are given to the same
types of pleasure automobiles, they may be gen-
erally classified as runabouts, roadsters, toura-
bouts, touring cars, town cars or taxicabs, lan-
daulets, limousines and semi-limousines. Elec-
tric automobiles are generally divided into
coupes, brougham, stanhopes, runabouts, phae-
tons, etc. Steam cars follow the same genera)
classification as gasoline machines. Commer-
cial vehicles may be classified as taxicabs, deliv-
ery wagons, trucks, busses, wagonettes, ambu-
lances, patrol wagons and other forms for fire
service.

Commercial Vehicles. In the commercial
vehicle field steam, electric and gasoline ma-
chines are used. Electric vehicles are used for
certain purposes, from heavy trucks to light
delivery wagons, usually only for short dis-
tances. Steam power is not at present being
used to any extent for heavy trucks, whilei
tlie gasoline commercial is used for tracks,
business wagons and quick deliveries.

The commercial vehicle may be classed as
follows : Taxicabs, j^fcneral delivery, light trucks,
lusivy trucks, coal waijfons, sight-seeing cars,
hiissrs, ambiilanc(\s and particular other types
for s|)C('inl pni*])oscs.

Since, for fr<*noral purposes, the speed of com-
mereinl veliieles is smnll, they are not neces-
sarily erpiipped with hi^ih power, as a heavy

The AutomohUe Handbook 131

car, which would travel at a high speed, would
be apt to be dangerous. The speeds obtainable
range on an average between twenty miles per
hour for delivery wagons, to five miles per hour
for heavy trucks.

While there are many distinct types of car
bodies, there are more names in use than there
are bodies, because different makers often apply
different names to the same type of body, and
often list a certain type of body under a name
different from the one ordinarily accepted. This
practice makes it difficult to state positively that
a certain type of body will be called by a given
name by a maker although that particular body
is of its own distinctive type regardless of the
name applied in the catalogues.

Bodies may be classified according to the num-
ber of persons carried, whether they are wholly
or partly enclosed and according to the purpose

Fig. 50

Five-Passenger Touring Car

for which they are designed. None of these

divisions is very satisfactory, because some types

132 The Automobile handbook

would appear in more than one division. The
following definitions are those generally ac-
cepted.

Touting Car. This is an open ear, Figs. 50
and 51, for general purposes which may seat
four, five, six or seven persons, including the
driver. It hsis sides and doors, but when pro-
tection from the weather is desired the operator
uses a folding top and curtains.

Fig. 51
Seating Arrangement In Four-Paesenger Car

A touring car seating five is called a five-pas-
senger touring car, one seating seven is called a
seven-passenger touring car, and so on for any
number of passengers. The rear compartment of
a touring car is called a tonneau, the front com-
partment is called the driver's compartment.

Close-Coupled oh Tov Tonneau. A four-
passenger touring car with the rear seat brought
well forward is sometimes called by one of these
names.

Torpedo, This is a touring car having the
body as small and low as possible while seating

The Automobile Handbook 133

the number of passesgers desired. The body is
of a form that offers the least resistance to wind

pressure and is called "stream line" in shape.

Runabout. This is an open body seating two
passengers, mounted on a comparatively small,
light or low powered chassis for use in town and
city travel and short country trips.

Fig. 62
Two-Passenger Roadster

Roadster. This is also an open body, Fig. 52,
seating two passengers, but mounted on a chassis
whose size, weight and power fits it for heavy
work and long distance touring.

Speedster or Baceabout. This is a powerful
chassis carrying small, light seats for two pas-
sengers and designed for high speed work. The
body is made as small and light as possible with
"bucket" seats, floor, dash, gasoline and oil
tanks, but no sides or doors, and in most cases
without a top.

Limousine. This is a type of body, Fig. 53,
used mostly for town and city driving in bad
weather or during the cold season.

134 The AutomohUe Handbook

It Beats four, five, six or seven persona in addi-
tion to the driver. It baa s permanent top and
the rear compartment is entirely- eneloaed and
has full doors. The driver's compartinent is di-

Fig. 53
Ltmoualne Body

vided from the rear hy a partition and this com-
partment is only partly enclosed.

Berline OB Berlin. This type is exactly like
the limousine except that the driver's compart-
ment is fully enclosed and has full doors.

Sedan. This body is like the Berline, that ia
to say, fully enclosed, but there ia no partition
between the driver's and rear compartment.

Landaulet oe Landau. This is a Umooaiiie
which has the rear half of the passenger com-
partment closed with a top that ia rigid when
raised but that lets down like those tops of dobed
carriages in common use.

The A.utomobUe Handbook

135

Town Cab. This type has the rear compart-
ment entirely enclosed with full doors, and seats
four or five persons in this part of the car. The
driver's compartment is open, the same as in a
touring car. The driver may be protected by a
small canopy extending forward from the en-
closed portion.

Coupi

CoL-PE, This type of body, Fig. 54, is entirely
enclosed and has full doors. It may seat two,
three or four passengers in the enclosed part,
the driver being one of these. It is mounted on
a roadster chassis anil bears the same relation to
the roadster that the Sedan bears to the touring

Convertible Cottpe ok Sedan. These bodies
are built in such a way that they give exactly
the same appearance as a regular Coupe or Sedan
from either the ontside or inside. The upper

136 The Automobile Handbook

portion is removable so that the Coupe or Sedan
is converted into a roadster or touring ear, de-
pending, on the arrangement and number of
passengers carried. ^

Cabriolet or Couplet. A convertible coupe
may be called by either one of these names, both
meaning the same thing.

TaVXiCAB. A car used as a public vehicle and
being for hire according to certain designated
rates of fare is called a taxicab. It is fitted with
a ** taximeter" which records the distance trav-
eled and the time spent in waiting,. and automat-
ally computes and indicates the fare to be paid.

Taxicabs may be made from Jimousines, lan-
daulets or town cars, the landaulet being the
type most generally used.

CoMMERCLVL Car Bodies. Thcsc types Includc
those used for carrying merchandise and also
those used for carrying passengers as a business.
Commercial car bodies may be designated accord-
ing to the type of construction, the class of work
to be handled or the weight to be carried.

Truck Bodies. These include the express,
platform, stake and panel types, and also many
special designs. Truck bodies are usually made
from designs prepared for each individual job
and according to the customer's requirements,
except in the lower priced cars.

Passenger Bodies. These include taxicabs,
sight seeing cars, carrying from eight to twenty
persons, and closed bodies suitable for carrying
passengers and baggage in interurban work.

The Automobile Handbook

137

Brakes. A brake is a mechanism which is
a necessary part of the machinery of an auto-
mobile and enables the operator by exerting a
slight amount of force on a lever to reduce the

138 The Automobile Handbook

momentum of the moving car. Brakes used on
automobiles may be divided into three classes:
Hub or rear wheel brakes, transmission and
diit'erential gear brakes. Brakes have also been
applied to the tires of the rear wheels, but
have proved unsatisfactory *and have been aban-
doned. The forms of brakes in use are single,
or double-acting, foot or hand operated, and of
the band, block or expanding ring types.

Figure 55, at A, B and C, shows three forms
of th(^ simplest type of single-acting band-brake.
This type of brake can only be operated success-
fully with the brake wheel running in one
direction only, which is indicated by the arrows
in the drawing. If the brakes be operated in
the reverse direction to that indicated by the
arrows the result will be to jerk the lever or
pedal out of the control of the operator of the
car.

The three forms of band-brakes shown at A,
B i\u(\ C are all of the same principle, the differ-
eiic(» being in the location of the fixed end of
tin' ])i'ak(^-band and the shape of the operating
1('V(M\ Typ(» 1) is a form of double acting block-
br;ik(% which is designed with a view to elimi-
nat(^ any strain or side thnist upon the shaft of
tli(^ ])nike wluM'l which may be caused by the
bi'jiking action of the d(»vice. Types B, G and
II nrc thrcH^ types of (l()u])le acting band-brakes,
in wliicli the ])rake may ])e applied with the
brnke wheel running in either direction.

Type F is a form of double acting block-brake,

The Automobile Handbook

139

in which the right hand ends of the brake-shoe
arms are pivoted to stationary supports, and
the left hand ends connected together by means
of a link and bell-crank lever as shown in the
drawing.

Fig. 56

In Figure 56 a form of double acting block-
brake I is shown, which is extremely powerful
on account of its peculiar construction, in that
is has a double leverage upon the brake wheel,
which may be readily seen by reference to the
drawing. Types J and K are of the form known

140 The Automobile Handbook

as internal brakes and of the expanding ring
type, the brakes operating upon the inner sur-
face or periphery of the brake wheel, instead
of the outside. They are known as hnb brakes,
beinfi usually attached to the hubs of the rear
wheels of the ear. Type L shows a form of
blook-brake in which the pivoted brake arms
are drawn top^ether by the eccentric located on
the brake lever shaft. When the lever is re-

Mg. 57

leased the brake-slioc arms are forced apart by
the iietion of the coil spring between the upper
ends of the arms.

Exi>ANDiNQ Bkake. In the internally expand-
ing brake, Fifnire 57, a hollow metal drum or
pnllcy D is carried upon some continuously
revolvinji portion of the ear mechanism, and
within this drum iire supported two metallic
shopR B B, which conform in shape to the in^de

The Automobile Hamdbook 141

sarface of the drum by means of a spring, S S.
The shoes are capable of being strongly pressed
against the revolving inner surface of the drum
by means of a cam or toggle arrangement, T,
operated through a wire rope or metal rod, R,
from the operator's lever or pedal. It is im-
portant that brakes of both these types should
have their bands or shoes so arranged that an
equal frictJonal effect is produced upon their
drums for a given force applied by the operator.

whether the vehicle is running forward or back-
ward. A brake so arranged is said to be double
acting. Another type of expanding brake is
shown in Figure 58, where D is the brake drum ;
S S, the brake shoes ; T, the toggle arrangement
which connects with the brake lever, and N is
a nut which is used for adjusting the movement
of the brake shoes.

Advantaoes op the Expanding Brake. The
expanding brake is coming more and more

142 The Automobile Handbook

into general use, and is taking the place of
the contracting brake in many eases, although
the latter is still being used extensively as an
emergency brake.

The advantages of the expanding brake are :
(1) it is less liable to drag upon the drum; (2)
it is easily made double actmg; (3) it has more
braking power for a given pressure; (4) the
friction surfaces are better protected from mud
and grit.

A form of brake designed for heavy service is
that known as the *' hydraulic," in which the
braking force is carried by means of oil through
suitable piping from a compressing cylinder to
a working cylinder. The lever operated by the
driver is located in the usual place and is con-
nected to the piston of a powerful oil pump.
From this pump connections, lead to a similar
cylinder on the chassis and from the piston and
plunger of this second cylinder connection is
made with the usual forms of brake mechanism.
The pump is operated by successive strokes of
the lever that increase the pressure; while the
brakes are released by pressing a button that
opens a valve and by releasing the hand lever.

Brake Linings. For expanding brakes, metal
shoes have become standard, owing to the prac-
ticability of maintaining proper lubrication be-
tween the frictional surfaces. In external
brakes the metal band is provided with some
form of nonmetallic lining that forms the brak-
ing surface applied to the drum. The reason

The Automobile Handbook 143

for this is that it is practically impossible to
properly lubricate an external brake. Various
kinds of material, viz., leather fabric, asbestos,
vulcanized fibre and camel's hair belting, are
used for lining external brake bands. A ma-
terial which is used for this purpose must have
great resisting powers, a constant co-efficient
of friction, even in the presence of oil and
water, and it must have the ability to resist
the influence of heat due to the brake's action.
In practice it has been found that leather lined
brakes burn out, and fibre linings become brittle
and cannot be depended upon, so that inorganic
materials, which cannot be carbonized, such as
asbestos fibre, are widely used. Asbestos fibre
may be readily woven into a fabric which an-
swers this requirement, but when used by itself
its strength is not sufficient. When, however,
it is woven over a metal wire gauze foundation
it appears to have the necessary stability to
withstand very severe service, and this is the
method employed in manufacturing the incom-
bustible brake linings which are being used.

Cork is the bark of the cork tree, and is the
lightest known solid. Its weight is one-eleventh
of aluminum, and one-thirtieth of cast-iron. It
has a very high co-efficient of friction, and is
not affected by many of the conditions which
seriously impair the efficiency of other sub-
stances.

Cork possesses qualities which distinguish it
from all other solids, namely, its power of alter-

144 The Automobile Handbook

ing its volume to a very marked degree in con-
sequence of a change of pressure. It consists,
practically of an aggregation of minute air ves-
sels, having thin, water-tight, and very strong
walls, hence, if compressed, the resistance to
compression rises in a manner more like the re-
sistance of a gas, for instance, than to that of
an elastic solid, such as a spring. The elasticity
of cork has a wide range and is very persistent.
It is this elasticity which makes it valuable when
used as an insert in a metal shoe. Cork is of
rather a brittle nature, though extremely strong,
and for that reason it cannot be used in the form
of a lining or facing. The method of applica-
cation is to insert corks in holes in the brake
provided for the purpose. Cork is not particu-
larly affected by heat or oil, and will largely in-
crease the efficiency in any application to a
brake or clutch.

Where metal-to-metal surfaces, with or with-
out cork inserts, are used, the surfaces are usu-
ally of different materials. The most common
material for drums in all cases is steel, but that
of shoes is either malleable cast iron, brass or a
bronze. Different metals make a better wear-
ing surface, and some combinations will have a
higher degree of friction adhesion than others.

In the selection of material for brake linings,
the co-efficient of friction is an important factor
to be considered. Table 7 gives the relative
values existing in combinations of different
materials.

The Automohiie Hwndbook

145

TABLE 7.

Co-efl9cient
Material — of friction

Metal to Wood 0.25 to 0.50

Metal to Fibre 0.27 to 0.60

Metal to Leather 0.30 to 0.60

Metal to Metal 0.15 to 0.30

Metal to Cork 0.36 to 0.65

Equalizers. In connection with all brakes
Tvhich are used in pairs, some method is used to
equalize the pressure of the brake handle or foot
pedal so that the same pressure will be applied

Fig. 59
Floating Lever Type of Equalizer

to both brakes. If the power is not equally ap-
plied to each brake, side slip or *' skidding'' will
result.

The different methods of equalizing brakes are
shown in Figs. 59, 60, 61 and 62, the majority of
ears using what is known as the floating lever
type, the cable arrangement being used only on
several makes of cars. The floating lever type

146

The Automobile Handbook

of equalizer is illustrated in Fig. 59. L is the
floating lever, connected at its central point to
the brake lever, or pedal by means of rod R.
The ends of lever L are connected to the brakes
B, B, by means of the brake rods C and D.
When rod R is drawn forward, lever L draws
rods C and D forward thus giving an equal pres-
sure on the hub brakes.

Fig. 60 shows another type of floating lever
equalizer. Shaft S connects to the brakes by

^—

Fig. 60
Floating Lever Equalizer

means of rocker arm^ located just outside the
frame. Two rocker arms, C and D are con-
nected to shaft S, and to the equalizing lever L
bv means of rods E and F. In some eases the
eciualizing lever is located outside of the frame.
It then takes the form shown in Pig. 61, in
which L is the lever that equalizes the pressure
on ])oth brakes connected to shaft S. Pig. 62
shows the arrangement of the cord equalizer.
Shaft S is connected to the two brakes, one »*

The Automobile Handbook

147

h end, and it has two rockers, or cranks B
I F attached to it. Parallel to S is another
ft C, which carries a grooved roller R. A
le is connected to crank E, carried over R,
I then passing baiek, is connected to crank F.
ten R is moved in the direction of the arrow,
the brake lever, the cord distributes the ten-
1 between E and F, and as a consequence the
ke also. This type is much cheaper than
others, but it reauires more care and atten-

Fig. 61
(^ Equalizer Lever Outside the Frame

Fig. 62
Cord Equalizer

148 The Automobile Handbook

Brazing. Many workmen labor under the im-
pression that a brazing job cannot be done un-
less the parts are a loose fit, in order, as they
say, to allow the brazil? g material to enter and
form a bond. The result Is, when they do the
work, the parts are a very loose fit, with accen-
tuated shearing tendencies in the section of the
bra zing material, and if the brazing happens to
be poorly done, the result is anything but good,
since, in the absence of brazing, there is not
evpu a good mechanical bond.

A good mechanical bond is possible to procure
ivithout, in any way, interfering with the braz-
ing process, since the parts, if they are well
fluxed, will take a coat of brazing material, even
when the recess is but a thousandth or two. In
brazing, if the work is to be up to a sufficient
standard to use in steering gear, it is necessary
to clean and brighten the surfaces in a most
thorough manner. This will best follow by me-
chanical scraping rather than by dipping in
some corroding material. Dipping may be of
value as a preliminary, but a file, and scraper,
in the hands of a man of competence, will go a
long ways toward success.

When the parts are well brightened, and the
grease is thoroughly removed, by the use of
soda water, benzine, or equally good solvents,
it remains to flux the parts with borax, and
then apply the heat, either by a forge or from a
special form of brazing torch which uses gaso-
line, kerosene, or other fuel oil, to pro-
duce the necessary heat. All forms of burn-

The Automobile Handbook 149

rs have means of adjusting the flame, and
ivo or more burners are usually placed
1 such position that their flames strike
le work. Torches are similar to the
lunsen burner ; if fire brick, or clay, is used to
uild up around the parts, the heating process
^ill be attended with less difficulty, and the work
411 be better at the finish. A rather hard braz-^
ig material may be used. This may be pur-
based ready for use, and there is no reason at
U why a motorist of even slight skill cannot
lake a good job of brazing.

Gamshaft. Fig. 63 is a sectional view of a mo-
3r cylinder and illustrates the principle and ae-
on of the camshaft. In many motors one cam-
tiaft serves to open both intake and exhaust
alves, while in other motors there is a cam-shaft
>r each set of valves. Besides opening the valves,
tie cams determine the length of time the valves
emain open, also the speed with which it opens
nd closes. Referring to Fig. 63, A is the crank-
baft, P the piston, D is the cam-shaft which
arries the cam E. The speed of the cam-shaft
epends upon the type of engine. The one
[lown in Fig. 63 is driven at half the speed of
16 crank-shaft through the gear wheels B and
, B being one half the size of C. H is the
alve to be opened, which in opening must be
fted off its seat. This is done when the cam

revolves and raises the roller G on the lower
id of lifter rod F which extends upward rest-
[g against the lower end of the stem of valve

The Automobile Handbook

H, although between the two roda, or rather at
their point of contact are nut and lock-nut L,

111 ItR IjO^^ation

?or adjnstintr tho Icri^'tli of P whon timing th
valve. K is a s|)ini] sjn-iiij:. the function o

The Automobile Handbook 151

which is to close the valve, after the cam E trav-
els around and allows G to drop. Directly-
above valve H is the intake valve M, which in
this case opens downward. This valve opens
automatically, due to the suction of the piston
in moving downwards on the intake stroke, but
is kept closed during the compression and ex-
haust strokes of the piston, by the pressure in
the cylinder.

Modern forms of construction make the cam-
shaft and cams from one piece of steel, and the
cams are then said to be integral with the shaft.
This method makes it possible to place the cams
in exactly the right position at the factory, and
the danger of lost power from improper placing
is thus greatly reduced.

Carbon Deposit— Symptoms of. One of the
most fruitful sources of trouble in internal com-
bustion motors is that of the carbon deposit. If
the cylinders get too much oil, or if oil of a
heavy or inferior grade is used, a portion of it
will work up past the pistons, where it will be
evaporated or consumed by the intense heat,
leaving a deposit of carbon. This may be aug-
mented by too rich a mixture, which serves to
deposit film upon film of carbon on the inside,
and top of the compression chamber, and on the
head of the piston. The films thus formed will
in time commence to scale, and the projections
fused by the heat of the (^plosions will servo to
prematurely ignite the charge. The symptoms
are back-firing and knocking in the cylinders

152 The Automobile Handbook

— as if the spark were too far advanced. An
almost infallible symptom of excessive carbon
deposit in the cylinders is the motor showing
plenty of power at high car speeds, but deficient
in hill-climbing on high gear. At slow engine
speeds the incandescent carbon projections serve
to pre-ignite the charge, thereby reducing the
power of the motor. The cure is to take off the
cylinder head and scrape off the carbon deposit
from the top of the piston and inside of the cyl-
inder head. Carbon also will form on the porce-
lain portion of the spark plugs, thereby furnish-
ing a circuit which the high tension current may
follow, rather than jump the gap between the
points of the plug. Usually only a part of the
current will pass by way of the carbon film,
still leaving a weak spark at the points, which
in op(»n air, when testing plugs, may seem strong
enoiijz'h. This causes intermittent firing. The
symptoms are similar to a poor contact com-
mutator. This condition is diflScult to detect,
for the reason that when the plug is subjected
to the usual test of removing from the cylinder
and closing the electrical circuit, the spark is
seen to jump free and fat between the sparking
points. This is because electrical energy which
is sufficient to jump between two points i^-inch
apart in the open air will jump less than 1/16-
incli in th(* explosion chamber under 60 pounds
compression. The causes of overheating in
motors may be summed up as follows : Poor oil,
insufficient oil, bad mixture, slow spark, ob-

The Automobile Handbook 153

structed water pipe, low water and valves out
of time.

Lubricating oil is charged with the crime of
depositing carbon on the surfaces of the com-
bustion chamber, and this carbon in turn causes
* * bucking, ' \ and pre-ignition. It probably is true
that inferior cylinder lubricating oil will de-
posit carbon, to some extent, but the main trou-
ble is from the gasoline which will not vaporize
until it is allowed to contact with the hot cyl-
inder walls, and this process of reducing the
gasoline to vapor is bound to lead to a carbon
deposit for the same reason that wood is
** coked" if it is heated to a temperature of
about 650 deg. C, provided the amount of air
present is less than that which would cause
complete combustion.

154 The Automobile Handbook

Carburetors, Principles of. Internal combn
tion engines used for the propulsion of mot<
ears use gasoline for fuel in almost all case
Experimenting is now going on in the endeavi
to use kerosene or alcohol, and in some cas
even lower grades of fuel. Gasoline and ker
sene are secured by heating crude petroleu
until vapor is given off, and this vapor is passe
through pipes that are kept cool enough to co:
dense the vapor into a liquid. Alcohol is s
cured by the distillation of fermented veg
table matter, and may be secured in almo
any part of the country if suitable means f(
distillation were to be developed.

Before the gasoline is ready to bum in tl
engine cylinders, it must be turned into a gj
or vapor. If gasoline stands exposed to the a
it will vaporize at a comparatively slow rat
but if ejected from a small opening in a fii
stream it will turn to vapor and mix with a
much more rapidly. It is always necessary 1
mix the gasoline vapor with air in certain pr
portions to make a combustible mixture. Tl
instrument that turns the gasoline into a g]
and then mixes the gas with air is called tl
carhurcior and the process is called carbureiin,

Many forms of carburetors have been mai
and used, but all instruments now fitted are i
the type known as automatic float feed. Tl
spray nozzle is the small opening inside of tl
carburetor through which the liquid gasolii
is drawn when it is to be made into a vapo

The Automohite Handbook 155

Tlie nozzle opening Ib placed in a tut^e through
which the air must pass on its way to the engine
cylinders. See Pig. 64, One end of this tube
is open to the outside air and the other end
sttaches to the piping that goes to the engine
cylindera. The end. open to the air is called
the primary air intake.

Fig. 64

Float-Feed Carburetor Mixing Chamber and Air

Valve. A, Spray Nozzle. B, Adjusting Needle

Valve. C, Primary Air Intake. D, Auxiliary Air

Valve. E, Air Valve Spring. F, Throttle Valve.

"When the piston travels away from the cylin-
der head on the inlet stroke, the inlet valve
opens and a cylinder full of mixture is drawn
from the carburetor. The air to make the mix-

156 The Automobile Handbook

ture is drawn through the carburetor primary-
air intake and must pass by the nozzle opening.
The gasoline is maintained at a height slightly
below the nozzle opening, and the suction, or
partial vacuum, of the incoming air causes
some of the gasoline to be drawn out of the
nozzle so that its spray mixes with the air.
This is the principle on which all modem car-
buretors operate, but certain added features
are necessary to compensate for the different
conditions obtaining under different rates of
car speed and engine load.

The first difficulty that would be encountered
with the simple form of carburetor just de-
scribed would be that of a falling gasoline
level in the nozzle as the fuel was drawn into
the engine. This would finally result in a fail-
ure of the fuel supply and stoppage of the
engine. In actual practice, the gasoline from
the car's tank does not pass directly into the
nozzle, but goes first into a small tank on the
carburetor, which tank is called the float cham-
ber. Of the two openings in this small tank,
one goes to the gasoline supply and the other
communicates with the carburetor nozzle. In-
side of the float chamber is a piece of cork cov-
ered with shellac or else a hollow metal cylin-
der, either of which will float on the surface of
whatever gasoline may be in the chamber. At
the opening of the pipe that comes into the
float chamber from the gasoline tank is a small
valve. Fig. 65, operated by connections at-

The AutomohUe Bandbooh 157

tached to the float itself. When the float is
low down in the chamber this valve is open;
bat as the float rises on the surface of the liquid
coming from the tank, it Anally reaches a height

Carburetor Float Valve Mechanism. A, rioat. B.

Float Lever Pivot. C. Float Lever. D, Float

Valve. B, Gasoline Inlet,
at which the valve is closed, and it will there-
fore be seen that the level of the liquid cannot
rise above the point determined by the position
of the float when the valve closes. When gaso-
line is drawn from the float chamber, through
the nozzle, the float falls with the fuel level
until the valve is again opened, and by this
repeated action the level is maintained constant

Other parts of the carburetor, such as the
anxiliary air valve, are described in the follow-
ing pages and the construction and adjuatmaiA
of tbe well known makes are taken ttp.

158 The Automobile Handbook

Almost any carburetor will give a reasons
good mixture through a limited range of act
Frequently, however, this range is found in;
ficient for a particular engine. If right for
speeds, it is wrong for high speeds, and
versa.

The theory of carburetor action as regf
the behavior of the gasoline jet under diffe]
air velocities is still only partially underst<
and has been the subject of a great deal
more or less blind theorizing, based in m
cases on wholly inadequate data.

A non-automatic spraying carburetor (i. e
simple nozzle in an air tube) makes no mixl
at all till the velocity of the air stream rea(
a certain minimum. Beyond this point,
richness increases with the speed. Dilu
from the auxiliary valve is therefore requi
only when the richness of the mixture exc(
the normal. At this point it should be rem
bered that, so far as the spray is conceri
there is no difference between a wide open th
tie at slow engine speed (as for instance,
hill) and reduced throttle with high en^
speed. The spraying action is concerned c
with the velocity of the air past the nozzle
fore the throttle is reached.

Almost every carburetor is provided with
needle valve controlling the spray orifice. "\^
this provision it is very easy to detem
whether or not the carburetor is doing as ^
as it should at either low or high speed.

The Automobile Handbook 159

example, suppose we start with an adjust-
ment known to be satisfactory for medium
speeds. If the low speed performance is under
suspicion, it is only necessary to increase the
needle valve opening slightly to ascertain
whether starting is thereby made easier, and a
walking pace more smoothly maintained. If
overheating results, reducing the needle open-
ing will probably cure it. Similarly slight
changes in the needle opening, without chang-
ing any other adjustment, will determine
whether or not the mixture is improved by
less, or more gasoline dt high speed. When the
carburetor is set for a medium speed, if the mix-
ture is weak at low speeds, and rich at high
speeds, more air should be admitted, but if the
mixture is rich at low speeds, and weak at
high, less air should be admitted. Much de-
pends upon the spring.

It is a characteristic of all springs that their
flexure is in direct proportion to the load im-
posed, up to the elastic limit of the spring.

The Float Feed Carburetor, Fig. 66, con-
siists of two principal parts : a gasoline recepta-
cle which contains a hollow metal or a cork
float, suitably arranged to control the supply of
gasoline from the tank or reservoir, and a tube
or pipe in which is located a jet or nozzle in
csommunication with the gasoline receptacle.
This tube or pipe is called the mixing chamber.
The gasoline level is maintained about one-six-
teenth of an inch below the opening in the jet

,60 The Automobile Handbook

The Automobile Handbook 161

in the mixing chamber. The inductive action
of the motor-piston creates a partial vacuum in
the pipe leading from the mixing chamber of
the carbureter to the motor, thereby causing
the gasoline to flow from the jet and mixing
with the air supply, to be drawn into the cylin-
der of the motor in the form of an explosive
mixture.

Spraying Carburetors. In this type of car-
buretor the quantity of gasoline delivered is
not proportional to the volume of air delivery
at different rates of flow. This difficulty has,
however, been met by providing a supplemen-
tary air inlet to the carbureter, which may be
regulated by the driver at will.

Another method of correcting the variations
in the. proportions of the gasoline charge is
shown in Fig. 67, and consists in providing a
second spray nozzle. In the majority of cases
in which multiple nozzle carburetors are used,
there are two nozzles, practically two carbure-
ters, a small one for idle running, and slow
speeds, and a larger one for heavy work. In
some instances, three, and even four nozzles are
used.

The Venturi Tube Carburetor operates on
the principle that if two converging air nozzles
have their small ends brought together, there
is a point where the suction remains practically
constant, therefore if the fuel nozzle be located
at this point the result will be, a constant mix-
ture at all speeds. In a carburetor of this type

162

The Automobile Handbook

there are no auxiliary spring controlle<
valves, no moving strangling cage, nor an;
chanical interregulation between the air
the gasoline.

An elementary Venturi tube is shown ir
68, which represents the tube A having a
of water on it. The discharge at A is gi
increased by the addition of the divergenl
zle at the outlet end. Under these condi

Fig. 68
Principles of the Venturi Carburetor

the velocity of flow in the throat at A is g]
than that produced by the head H. WJ
pressure gauge is placed at A the pressi
found to be less than atmospheric; in fac
fluid is discharging into a partial vacuun
the velocity at A is due to the head H pli
head due to the vacuum. Advantage is
of this fact by placing the gasoline out
the point A, in which case the velocity c

The Automobile Handbook 163

suction controls the flow of gasoline at all limes
thus giving a perfect mixture.

AuxniiiARY Air- Valve. It has been deter-
mined from the result of experiments that to
get the maximum power at any speed from a
gasoline motor equipped with a float-feed car-
buretor, the jet of the carburetor must have a
larger opening for low speeds than for high
speeds. As this practice would require a very
delicate adjustment it consequently becomes
almost impracticable, because necessitating a
constantly varying regulation for each frac-
tional variation of speed of the motor. The
difficulty may be obviated by the use of an aux-
iliary air-valve, located in the induction-pipe
close to the inlet-valve of the motor.

The jet of the carburetor is set for the maxi-
mum quantity of gasoline at the slowest speed
of the motor, and as the speed is increased the
auxiliary air-valve comes into action and re-
duces the supply of air passing through the car-
bureter, thereby reducing the suction or partial
vacuum at this point, and maintaining a con-
stant quality of mixture at all times.

The auxiliary air valve has been attached to a
dash pot construction in many makes of modern
carburetors. The dash pot may operate with
air or with gasoline for its fluid, but in either
case the purpose is to prevent sudden opening
and closing of the valve or ** fluttering. ' ' Such
fluctuation is a cause of noise and also tends
to destroy the proportions of the mixture.

164 The Automobile Handbook

Frequently it is observed that the intake to
the carburetor is so restricted that noise issues,
and a little further investigation in such cases
will disclose, in all probability, that wire-draw-
ing is one of the ills. It is not alone the noise
that is objectionable in such eases; the power
of the motor will be less, due to the restriction
which has the effect of reducing the weight of
mixture that enters into the cylinders, and the
power of a motor is undoubtedly proportional
to the weight of mixture that enters the cylin-
ders, assuming, of course, that the same is in
acceptable form, and that it is completC'ly
burned. True, there must be a depression in
the carburetor in order that there will be a dif-
ference in pressure, so that gasoline will be
sucked into the train of air ; equally true, it is
of the greatest importance to have the depres-
sion as low as possible in order that the power
of the motor will be a maximum. If the depres-
sion is but slight, provided the carburetor is
properly designed, the amount of fuel entrained
will be adequate for the purpose. If, on the
other hand, the depression is very large and
holds considerable fuel, it will soon be found to
be wasteful of the liquid.

"With the low grades of fuel now in use, wire-
drawing is very harmful, inasmuch as it tends
to separate the gasoliue from the air and causes
the gasoline vapor to again become a liquid and
deposit on the tubing walls.

The Automobile Handbook 165

Effect of Cold on Oasoline. The tempera-
ture has a very marked effect on the rapidity
with which gasoline vaporizes, and in cold
weather it is necessary to supply heat to the
carburetor.

The carburetor should preferably be jacket-
ed, and it may be warmed either from the circu-
lating water, or by taking a small quantity of
the hot gases from the exhaust pipe. If water is
used it should be taken from a point just be-
yond the discharge of the pump, and should be
delivered to the return pipe from the engine
jacket to the radiator.

Whether exhaust gases or water is used, the
flow should be regulated by a cock, otherwise
too much heat will be received in warm weather.
When the carburetor is cold, the engine may be
started by pouring warm water over it, care be-
ing taken not to let any portion of the water
get into the gasoline through any aperture in
the top. Another method of warming up the
carbureter is to wring cloths out of hot water,
and wrap them around it.

While it is not generally realized, the flow of
gasoline through the nozzle is greatly influenced
by the temperature of the liquid. Gasoline at
very low temperatures, such as freezing, and
slightly above, is reduced as much as 30% in
volume of flow below the point reached when the
liquid itself is warmed to between 65° and 80°
Fahrenheit. This forms one more reason for
jacket heating on all carburetors.

166 The Automobile Handbook

Carburetor Inspection. The float valve of
the carburetor should be tested for leaks by
opening the valve between it and the tank and
looking for gasoline drip. If gasoline escapes,
it may simply be because the float ia set too
high, so that it does not close the needle valve
before gasoline issues from the spray nozzle.
Or, it may be that the valve itself leaks.

At this stage, it is well to assume that the
float is properly adjusted, and to begin by shut-
ting ofl:* the main gasoline valve, and then un-
screwing the washout plug below the needle
valve. It may be found that dirt, waste, or a
splintt^r of wood has got past the strainer,
through which, presumably, the gasoline passes
on its way to the float, and is lodged in the
iioedle-valve opening. It may be of advantage
to open the top of the float chamber, which can
usually be done without disturbing other parts,
and take out the float and needle valve. A lit-
tl(^ gasoline washed down through the needle-
valve oi'ifice will thi^n generally carry away any
dirt that may have clung to the valve when the
])lii<r was unscrewtMl. If the gasoline still drips
when the ])arts are r(^ass(*mbled, the mixing
rliniiilx'r sliouhl b(^ opc^ncd and the top of the
spr*ay nozzle examined to see if gasoline is es-
ea])iim' from it. An el(H'tri'» light should be
used iu iiiakiMg an examination of the carbu-
reter, as. with aMv otlier illuminant, a fire might
bo started. The ])ortable electric flashlights
answer the j)urpose very well.

The Automobile Handbook 167

Occasionally a carburetor is found to be too
large for the engine, or to have too large a
spray orifice. The advice has been given in
such a case to reduce the size of the spray ori-
fice by lightly pening the top of it with a ham-
mer. This is counsel of doubtful value, even
if the hole be afterward reamed true, since it is
manifest that the burr formed in the top of the
orifice cannot possibly be deep enough to be at
all regular in its form. It will almost inevita-
bly throw a jet slantwise, instead of straight,
and this je^ failing to strike the main part of
the air stream will be only partly atomized,
with resulting misfiring and general bad be-
havior, especially at low speeds. If a new noz-
zle of smaller size cannot be substituted, the
best thing to do in case there is no needle valve
to adjust the flow of gasoline to the jet is prob-
ably, to warm the ingoing air as much as possi-
ble, in order to make evaporation by tempera-
ture take the place of atomizing due to the air 's
velocity.

Holly Carburetor, Model H. This carbure-
tor is shown in Fig. 69. Before the fuel enters
the float chamber it passes a strainer disk A
which removes all foreign matter that might in-
terfere with the seating of the float valve B
under the action of the cork float and its lever
C. Fuel passes from the float chamber, D, into
the nozzle well E, through a passage F, drilled
through the wall separating them. From the

168

The Avtomobile Handbook

nozzle well the fuel enters the nozzle proper, G,
through the hole H, and then rises past the
needle valve I, to a level in its cup-shaped upper
end, which just submerges the lower end of a
small tube, J, which has its outlet at the edge of
the throttle disk.

Fig. 69
Holly Carburetor, Model "H"

Cranking the engine, with the throttle kept
nearly closed, causes a very energetic flow of air
through the tube J and its calibrated throttling
plug K, but the lower end of this tube is sub-
merged in fuel, with the engine at rest. There-

The Automobile Handbook • 169

fore, the act of cranking automatically primes
the motor. With the motor turning over, under
its own power, flow through the tube J takes
place at very high velocity, thus causing the fuel
entering the tube with the air to be thoroughly
atomized upon its exit from the small opening
at the throttle edge. This tube is called the
**low speed tube" because, for starting and idle
running, all of the fuel and most of the air in
the fuel mixture are taken through it.

As the throttle opening is increased beyond
that needed by idling of the motor, a consider-
able volume of air is caused to move through the
passage bounded by the conical walls L of the
so-called strangling tube. In its passage into
the strangling tube^ the air is made to assume an
annular, converging-stream form, so that the
point in its flow at which it attains its highest
velocity is in the immediate neighborhood of the
upper end of the **standpipe" M, set on to the
body of the nozzle piece G. The velocity of air
flow being highest at the upper, or outlet, end of
the standpipe, the pressure in the air stream
is lowest at the same point. For this reason
there is a pressure difference between the top
and bottom openings of the pipe M, thus causing
air to flow through it from bottom to top, the air
posing downward through the series of open-
ings N in the standpipe supporting-bridge and
then up through the standpipe.

With a very small throttle opening, the action
through the standpipe keeps the nozzle thor-

^tuLoJ-^:

170

The Automohile Handbook

oughly cleaned out, the fuel passing directly
from the needle opening into the entrance of the
standpipe. To secure the utmost atoraization
of the fuel, the passage through the standpipe is
given aspirator form, which further increases
the velocity of the flow through it, and insures
the greatest possible mixture of the fuel with the
air, A further point is that the atomized dis-
charge of the standpipe enters the air stream at
a point at which the latter attains its highest
velocity and lowest pressure.

Fig. 70
Holly Carburetor, Model "G"
There is but one adjustment, the needle valve
I, The effect of a change in its setting is mani-
fest equally over the whole range of the motor.
Holly Carburetor, Model G. This design is
especially for Ford cars. Its method of opera-

The Automobile Handbook 171

tion is identical with that of the Model H, its
chief differences as compared with the othei^
model being structural ones, giving a horizontal
instead of a vertical outlet, a needle valve con-
trolled from above, and a general condensation
of the design to secure compactness.

Fuel enters the carburetor, shown in Fig. 70,
by way of a float mechanism in which a hinged
ring float, in rising with the fuel, raises the float
valve into contact with its seat. The seat is a
removable piece and the float valve is provided
with a tip of hard material.

From the float chamber the gasoline passes
through the ports E to the nozzle orifice in
which is located the pointed end of the needle
F. It is noted that the ports E are well above
the bottom of the float chamber, so that, even
should water or other foreign matter enter the
float chamber it would have to be present in a
considerable quantity before it could interfere
with the carburetor operation.

A drain valve D is provided for the purpose
of drawing off whatever sediment, or water, may
accumulate in the float chamber. The float level
is so set that the gasoline rises past the needle
valve F and fills the cup G to submerge the
lower end of the small tube H. Drilled passages
in the casting communicate with the upper end
of this tube with an outlet at the edge of the
throttle disk. The tube and passage give the
starting and idling actions, as described in con-
nection with the Model H.

172 The Automobile Handbook

The strangling tube I gives the entering air
stream an annular converging form, in which
the lowest pressure and highest velocity occur
immediately above the cup G ; thus it is seen that
the fuel issuing past the needle valve F is imme-
diately picked up by the main air stream at the
point of the latter *s highest velocity.

The lever L operates the throttle in the mix-
ture outlet, and a larger disk with its lever S is
a spring-returned strangler valve in the air in-
take, for facilitating starting in extremely cold
weather.

The Automobile Handbook X73

Kingston Carburetor. The Kingston carbu-
retor, Fig. 71, uses a ball type of auxiliary

, Fig. 71

__^ pKingatoii Ciirburetoi
air valve instead of the employment of spring
control dashpot, diaphragm or auxiliary air
valve. The main air intake A communicates
with the vertical mixing chamber B, in which
the sides C are beveled outward, giving a center
tube eifeet, so that the air current converges
above the nozzle N, as indicated by the arrows.
D marks the exit to the motor controlled by the
butterfly throttle E. Auxiliary air enters
through five circular openings G, arranged in
a semi-circle in the floor of an extension H of
the mixing chamber. Each of these five open-
ings consists of a bushing K threaded into the
opening in the extension H, and having its top
beveled to receive a five-eighths inch bell metal
bronze ball Ji. which is retained in position by
a threaded bushing M, fitting in the top of the
extension H. It has a pair of downward project-

174 The Autofnobile Handbook

ing hooks N for preventing the ball getting out
of position, but not interfering with the ball
rising vertically when forced to do so by the
pull of the motor, at which time additional air
is admitted. Two others of the five auxiliary
entrances are shown at I and O, all of the five
containing balls of the same size and weight.
The air entering through the openings guarded
by these balls has an imrestricted passage into
the mixing chamber and thence to the motor.
Any ball is easily moved by unthreading the
cap M, after which the ball can be lifted out.

The gasoline enters the carburetor from
the gasoline tank by way of the connec-
tion J, which is guarded by the needle valve R,
operated through the lever S, pivoted in the
side of the casting and with its long arm bear-
ing on the top of the cork float. The float is
fitted with a metal bushing. Complete control
of the nozzle N is through the needle valve V,
which, at the top of the carbureter, has a T-
piece X, by which it can be raised or lowered,
thereby regulating the flow of gasoline. A
feature of the throttle connection T is the ser-
rated lower face of its hub W, so that by loos-
ening a lock nut Z, the handle T may be turned
in any direction most convenient. The air in-
•take A consists of an L-shaped piece secured
to the carbureter casting by a nut P, and in the
base of this is a circle of openings F where cur-
rents of air can enter, the object of these open-
ings being that by priming the carburetor, and

The Automobile Handbook 176

overflowins: the open mouth of nozzle N the
gasoline falls to the vicinity of the holes F, and
the air entering through these openings will
facilitate the breaking up of the gasoline, and
thereby assist the starting of the motor.

Krebs Carburetor. In the Krebs style of car-
buretor, a constant proportion of gasoline and
air is maintained by means of suitable sections
of air and gasoline outlets. The openings, are
so arranged that a proper mixture is main-
tained at minimum suctions, after which grad-
ually increasing quantities of supplementary
air are admitted.

A number of attempts have been made to im-
prove upon the Krebs principle by variously
shaping the supplementary air openings, or the
spring on the supplementary air valves, so as
to insure complete compensation for the in-
creas.e in richness of the mixture formed in the
spray chamber with increasing suction, by the
addition of the correct amount of supplemen-
tary air at all suctions. The mixture formed in
an ordinary spray carbureter becomes richer as
the suction increases. At first the only means
provided to correct this 'defect was a hand-regu-
lated air valve; but since the advent of the
Krebs carbureter, practically all new carburet-
ers brought out have some arrangement for au-*
tomatically keeping the mixture constant, re-
gardless of variations in suction. In general
the means provided are close copies of the
Krebs supplementary air valve, though in some

176 The Automobile Handbook

instances this valve, instead of being aetu
by the suction, is operated either hydraulic
by means of a diaphragm in a chamber com
nicating with the water cooling system, or
chanically by direct connection with the tt
tie valve.

The Automobile Handbook 177

Master CAiffiUBETOR. This carburetor, shown
in Fig. 72, is unique in that it has no adjuBt-

ments, and is so simple that it may be readily
taken apart and put together again. In the
Master carburetor both the fuel and the air are
positively regulated. This regulation is accom-
plished by a rotary throttle, which not only un-
covers a series of minute holes in the fuel dis-

Fig. ;
Master Carburetor Vapor! zing Action

tributer, but eliminates the butterfly valve found
in most other carburetors. This action is shown
in Fig. 73. When the throttle is closed fuel is

178 The Automobile Handbook

admitted through but one hole, suflScient for slow
speed or idling. As the throttle is opened addi-
tional holes are uncovered, one by one, and the
fuel supply increased. The rotary valve does not
become worn, as it does not come in contact with
the throttle chamber in which it rotates. The

Fig. 74
Master Carburetor Damper

damper shown in Fig. 74 is a rigid plate, extend-
ing entirely across the passageway, paralleling
the fuel distributer. This damper lever is at-
tached to the hand control located on the steering
post by means of a steel wire passing through
a brass tubing. A trap is located under the float
chamber and it contains a brass screen that
filters the fuel, which is again filtered by an-
other screen of tubular form.

Rayfield Carburetor. The Rayfield carbure-
tor has no direct adjustment for the nozzle
opening such as would be provided by a screw
needle valve, but to take the place of such an
adjustment a type of lever mechanism is used
that increases or decreases the gasoline supply

The Automobile HandhooJc 179

according to the degree of throttle opening, and
also provides means for adjusting the fuel flow
for high or low speeds independently of each
other. Adjustment is provided through two
screws with milled heads, one of these serving to
fix the position of the nozzle adjustment at low
engine speed* or with a nearly closed throttle
and the other one operating only when the throt-
tle is more than half way open. The construc-
tion of this instrument is clearly shown in Figs.
75, 76 and 77, and the method of adjustment is
described on the following pages.

Model D, Fig. 75 — ^Adjusting low speeds: —
Close needle valve by turning low speed screw
to the left until arm U slightly leaves contact
with the cam. Then turn to the right one and
one-half turns, open throttle one-quarter, prime
carburetor and start motor. Close throttle until
motor runs slowly without stopping. Turn low
speed screw to the left one notch at a time until
motor idles smoothly. If motor does not throttle
low enough turn screw in stop arm to the 'left
with a screw driver. Carburetor is now adjusted
for low speed.

Adjusting high speed: — ^Now open the throt-
tie slowly until wide open. Should motor back-
fire turn high speed adjusting screw to the right,
a half turn at a time, until motor runs without
a miss. Should motor not backfire turn high
speed adjusting screw to the left until it does,
then to the right until motor runs smoothly and
powerfully.

180 The Automobile Handbook

Do not use low speed adjustment to get a cor-
rect mixture at high or intermediate speeds.

Should motor backfire or mixture be too light
at intermediate speeds (throttle about 14 open)

Fig. 75

Rayfleld Carburetor. Model "D". A. Float Cbam-
ber. B, Mixing Chamber. C, Flange. D, Throt-
tle Lever. E, Gasoline Intake. H, Gas Arm. J,
Dash Adjustment. K, Air Valve. L, Needle
Valve. M, Regulating Cam. P, Air Adjuatment.
R, Air Lock. S. Drain Plug. T, Priming Cap.
U, Needle Arm. F, Water Connection. O,
Priming Lever. N. Low Speed Adjustment. O,
High Speed Adjustment. V. Primary Air In-
take. W, Cam Shatt.

turn air valve adjustment P to the right a turn
or two, thus increasing the spring tension and
decreasing quantity of air slightly.

Remember that it is best to use all the air that
the motor will handle without being sluggish.

Do not change the float level. It is correctly
set at the factory. Always prime carburetor

The Automobile Handbook 181

well before starting motor. Pull steadily on
primer string. Don't jerk.

Do not cut down the air supply, unless the
gasoline adjustments fail to give you a powerful
and fast mixture.

If motor does not get the correct mixture at
intermediate speed or high speed, do not try to
remedy it through a low speed adjustment. Re-
member, the low speed adjustment is to be ad-
justed only when the motor is running idle.

In starting motor, do not open throttle more
than one-quarter. The motor will start more
readily with the throttle slightly opened and it is
harmful as well as useless to race the motor in
starting.

Before cranking motor pull dash button up.
After motor has '* warmed up'* push dash button
down to Running Position.

In stopping motor pull up dash button, open

throttle about i/4 inch, and switch off ignition,

thus leaving a sufficient volume of rich mixture

' in the cylinders, which assures easy starting

when the motor is again used.

Models G and L, Figs. 76 and 77, have no air
valve adjustment and only two gasoline adjust-
ments.

Always adjust carburetor with dash control
down. Low speed adjustment must be completed
before adjusting ''high.''

Adjusting low speed: — ^With throttle closed,
and dash control down, close nozzle needle by
turning Low Speed adjustment to the left until

182

The Automobile Handbook

^ |MieM-5F

(I>^

®V (

Bi^pJ

MCfi^l^A

GASOLINE
INTAHL

bk!!^

Fig. 76

Rayfleld Carburetor, Model "G". D, Throtl
6, Priming Lever. H, Gaaollne Arm. K
lating Cam, S, Drain Cock. U, Needl
Arm. X, Drain Cock. J, Gasoline Contr

The Automobile Handbook 183

Block U slightly leaves contact with the cam M.
Then turn to the right about three complete
turns. Open throttle not more than one-quarter.
Prime carburetor by pulling steadily a few sec-
onds on priming lever G. Start motor and allow
it to run until warmed up. Then, with retarded
sparky close throttle until motor runs slowly
without stopping. Now, with motor thoroughly
warm, make final low speed adjustment by turn-
ing low speed screw to left until motor slows
down, and then turn to the right a notch at a
time until motor idles smoothly.

If motor does not throttle low enough, turn
stop arm screw A to the left until it runs at the
lowest number of revolutions desired.

Adjusting High Speed: — ^Advance spark
about one-quarter. Open throttle rather quickly.
Should motor backfire it indicates a lean mix-
ture. Correct this by turning the high speed
adjusting screw to the right about one notch at
a time, until the throttle can be opened quickly
without a backfiring.

If 'loading" (choking) is experienced when
running under heavy load with throttle wide
open, it indicates too rich a mixture. This can
be overcome by turning high speed adjustment
to the left.

Adjustment made for high speed will in no
way aflfect low speed. Low speed adjustment
must not be used to get a correct mixture at high
speed. Both adjustments are positively locked.

Starting: — ^Before starting motor when cold

184

The Automobile Handbook

observe the following. Open throttle not more
than one-quarter. Enrich the mixture by pull-
ing up dash control. Prime carburetor by pull-
ing on priming lever G for a few seconds.

When stopping motor, pull up dash control.
Open throttle about one-quarter and switch oflf
ignition. This leaves a rich mixture in the
motor, which insures easy starting.

Fig. 78

Schebler Carburetor, Model "D". A, Auxiliary Air
Valve. C, Choke Valve. D, Drain Cock. F,
Float. M, Spray Nozzle. G, Gasoline Inlet. N,
Air Valve Adjustment. S, Air Valve Spring. T,
Throttle Valve Lever. V, Gasoline Adjustment
Valve.
Raising dash control enriches the mixture by

lifting the nozzle needle. Control button should
be down for running, except when a richer mix-
ture is required.

Pull button up full distance for starting.

The Automobile Handbook 185

Adjustment of carburetor should always be
jnade with dash control down and motor warm.

SCHEBLER Carburetors. This make of instru-
ment has been built in a number of different
models, the first one of which to be used in large
numbers was the Model D, Fig. 78. All of the
important types of Sehebler carburetors now in
use are described and instructions given for their
adjustments on the following pages.

Fig. 79
Sehebler Carburetor, Model "L". A, Auxiliary Air

Valve. B, GaBollne Needle Valve. C, Priming

Lever. D, iDtermediate Speed Cam. E, High

Speed Cam.

The Model L carburetor. Fig. 79, is a type of
lift needle carburetor and is so designed that the
amount of fuel entering the motor is automatic-
ally controlled by means of a raised needle work-
ing automatically with the throttle. The adjust-
ment or control of gasoline in this instrument

186 The Automobile Handbook

can be adjusted for low, intermediate or high
speed, each adjustment being independent and
not affecting either of the other adjustments.

In adjusting the carburetor, first make adjust-
ment on the auxiliary air valve A so that it seats
firmly but lightly ; then close the needle valve by
turning the adjustment screw B to the right
until it stops. Do not use any pressure on this
adjustment screw after it meets with resistance.
Then turn it to the left from four to five com-
plete turns and prime or flush the carburetor by
pulling up the priming lever C and holding it
up for about five seconds. Next, open the throt-
tle about one-third, and start the motor; then
close the throttle slightly, retard the spark and
adjust throttle lever screw F and needle valve
adjusting screw B so that the motor runs at the
desired speed and fires on all cylinders.

After getting a good adjustment with the
motor running idle, do not touch the needle valve
adjustment again, but make all intermediate and
high speed adjustments on the dials D and E.
Adjust pointer on the first dial D from the
number 1 towards 3, about half way between.
Advance the spark and open throttle so that the
roller on the track running below the dials is
in line with the first dial. If the motor backfires
with the throttle in this position, and the spark
advanced, turn the indicator a little more toward
number 3 ; or if the mixture is too rich turn the
indicator back or toward number 1, until motor
is running properly with the throttle in this posi-

The Automobile Handbook 187

tion, or at intermediate speed. Now, open the
throttle wide and make adjustment on the dial
E for high speed in the same manner as for in-
termediate speed on dial D.

In the majority of cases in adjusting this car-
buretor the tendency is to give too rich a mix-
ture. In adjusting the carburetor both at low,
intermediate and high speeds, cut down the gaso-
line until the motor begins to backfire, and then
increase the supply of fuel, a little at a time,
until the motor hits evenly on all the cylinders.
Do not increase the supply of gasoline by turn-
ing the needle valve adjusting screw more than
a notch at a time in the low-speed adjustment,
and do not turn it any after the motor hits regu-
larly on all cylinders. In making the adjust-
ments on the intermediate and high speed dials,
do not turn the pointers more than one-half way
at a time between the graduated divisions or
marks shown on the dials.

The Model E Schebler carburetor, Fig. 80, is
a single jet raised needle type of carburetor,
automatic in action. The air valve controls the
lift of the needle and automatically proportions
the amount of gasoline and air at all speeds.

The Model R carburetor is designed with an
adjustment for low speed; as the speed of the
motor increases the air valve opens, raising the
gasoline needle, thus automatically increasing the
amount of fuel. The carburetor has but two ad-
justments— ^the low speed needle adjustment,
which is made by turning the air valve cap and

188 The Automobile Handbook

an adjustment on the air valve spring for chang-
ing its tension.

This carburetor has an eeeentrie which acta on
the needle valve, intended to be operated either
from the steering eolumn or from the dash, and
insures easy starting, aa by raising the needle
from the seat an extremely rich mixture is fur-
nished for starting, and for heating up the motor
in cold weather. A choker in the air bend is also
furnished.

Fig.
Schebler Carburetor, Model "R". A, Low Speed

AdjUBtment. B, Starting Cam Lever. C, Needle

Valve Connection. D, Starting Cam. E, Needle

Valve. F, High Speed Adjustment.

When carburetor is installed see that lever
B is attached to steering column control or dash
control, so that when boss D of lever B is against
stop C the lever on steering column control or
dash control will register "Lean" or "Air."

The Automobile Handbook 189

This is the proper running position for lever B.

To adjust carburetor turn air valve cap A
3lockwise or to the right until it stops, then turn
:o the left or anti-clockwise one complete turn.

To start engine open throttle about one-eighth
)r one-quarter way. When motor is started let
t run till engine is warmed, then turn air valve
3ap A to left or anti-clockwise until engine hits
perfectly. Advance spark three-quarters of the
vay on quadrant, if engine backfires on quick
icceleration turn adjusting screw F up (which
ncreases tension on air valve spring) until ac-
celeration is satisfactory.

Turning air valve cup A to right or clockwise
ifts needle E out of nozzle and enriches mix-
;ure ; turning to left or anti-clockwise lowers the
leedle into nozzle and makes mixture lean.

When motor is cold or car has been standing,
nove steering column or dash control lever to-
wards '^Gas" or ''Rich'' which lifts needle E
)ut of gasoline nozzle and makes rich mixture
■or starting. As motor warms up, move control
ever gradually back towards ''Air" or "Lean''
;o obtain best running conditions until motor has
•cached normal temperature. When this tem-
)erature is reached control lever should be at
'Air" or "Lean."

For best economy and power, the slow speed
idjustment should be made as lean as possible.

Stromberg Carburetors are made with a noz-
zle, the opening in which is not adjustable. This
lozzle is a separate part of the carburetor and

190 The Automobile Handbook

is screwed into place from below. In order to
adjust the gasoline flow it is necessary to remove
one nozzle and replace it with one having a larg-
er or smaller opening. The nozzles are marked
according to drill gauge sizes and the opening
becomes larger as the number becomes lower, that
is to say, a number 59 is larger than a number
60 and a number 58 is larger than a number 59.

If, after making low speed adjustment it is
found that the air valve remains off its seat or
that indications of a rich mixture are still pres-
ent, the nozzle is too large. If the high speed
adjustment has to be screwed very tight it indi-
cates that the nozzle is too small. In changing
nozzles do so one size at a time, that is, do not
drop from number 60 to a number 58, but use
a 59 first.

The several types of Stromberg carburetors
that have been fitted up to the present time are
described and adjustment instructions given in
the following pages.

Instructions for type A. Type A, Fig. 81, is
a water jacketed carburetor. It has its spray
nozzle PN mounted in the center of the carbure-
tor with its point 3-16 of an inch above the
normal gasoline level and surrounded by a
modified venturi tube. This nozzle is propor-
tionate in size to the carburetor and never needs
attention or adjustment.

After the carburetor is installed and the gaso-
line turned on, note the level of the gasoline in
the float chamber. It should be about one inch

The Automobile Handbook

191

from the lower edge of the glass. This level ia
adjusted at the factory and should be right. In
case it is obviously wrong, remove the dust cap
D and turn the adjusting screw S until the
proper level is obtained. If the gasoline is too
high, screw the nut down. If gasoline is too
low, screw the nut up. Don't change unless
absolutely :

Fig.

Stromberg Carburetor, Model "A"
To start the motor close the valve S3 in the
hot air horn H. The motor should then start
on the second or third turn of the crank. If
not, open the valve and it ought to start on
the next turn. Great care should be taken to
see that this valve is instantly opened as the
motor starts, and is kept open.

Season adjustments. Open and close shutter
SA — open in summer and closed in winter.
Low speed adjustment. Turn up the adjust-

192 The Automobile Handbook

ing nut A until the spring SI, which is the low
speed spring, seats the valve lightly. See that
the high speed spring above B is free and does
not come in contact with the nut on top of the
auxiliary air valve stem. Start the motor and
turn nut A up or down until motor idles prop-
erly. This is the low speed adjustment.

High speed adjustment. Advance the spark
and open the throttle. If the motor backfires
through the carburetor, turn high speed adjust-
ing nut B up until backfiring ceases. If, with
this adjustment and running at low speeds,
motor gallops, or the carburetor loads up, the
mixture is too rich. The nut B should then be
turned down until galloping or loading ceases.
This is the high speed adjustment. The spring
above nut B should always have at least 1-32
inch clearance between it and the nut at the top
when the motor is at rest.

Instructions for type B. Type "B, Fig. 82,
is a concentric type carburetor. It has its spray
nozzle PN mounted in the center of the car-
buretor, and in the center of the float chamber,
with its point 3-16 of an inch above the normal
gasoline level and surrounded by a modified
venturi tube.

The level of the gasoline in the float chamber
should be about 15-16 of an inch from the lower
edge of the glass marked X. This level is adjust-
ed at the factory and should be right. In case
it is wrong, remove the dust cap D and turn
the adjusting screw S until the proper level is

The Automobile Handbook 193

obtained. If the gasoline is too high screw the
nut down. If the gaaoline is too low screw the
nut up. Don't change unless absolutely neces-
sary.

Fig. 82
Strombetg Carburetor, Model "B"

Low speed adjustment. Turn up the adjust-
ing nut A until the spring SI, which is the low
speed spring, seats the valve lightly. See that
the high speed spring above B is free and does
not come into contact with the nut on top of
the auxiliary air valve stem. Start the motor
and turn nut A up or down until motor idles
properly. This is the low speed adjustment.

High speed adjustment. Advance the spark
and open the throttle. If motor backfires
through the carburetor, turn high speed adjust-
ing nut B up until backfiring ceases. If, with
this adjustment and running at low speeds
motor gallops, or the carburetor loads up, the

194 The Auiomohile Handbook

mixture is too rich. The nut B should then be
turned down until galloping of loading up
ceases. This is high speed adjustment. The
spring atove nut B should always have at least
1-32 inch clearance between it and the nut at
the top when the motor is at rest.

Strom berg Carburetor, Afodel "C"
Instructions for type C. Type C, Fig. 83,
is equipped with two separate gasoline spray
nozzles. The first or primary nozzle PN is
mounted in the ■ronturi tube V; this nozzle
supplying sufficient gasoline for all speeds up to
twenty or twenty-five miles per hour. The sec-
ond or auxiliary nozzle is mounted just beneath
the secondary gasoline needle valve ANV in
the auxiliary air passage AA, and is opened by
the lever L operating over a fulcrum F by the
opening of the auxiliary air valve AV.

The Automobile Handbook 193

Turn up the lower adjusting nut N, located
underneath the auxiliary air valve, so that the
valve is brought up to seat, then give two full
turns to the right as a starting adjustment.
This valve should be seated on extreme idle.
The spring SI is the low speed spring and does
the work up to the opening of the auxiliary
needle.

Start the motor and turn low speed nut N up
or down until the motor idles properly, then
advance the spark, open the throttle, and if the
motor backfires turn nut LN down until it
ceases. If mixture is too rich, turn it up. Be
sure that nut LN and lever L have some clear-
ance on low speed.

The proper gasoline level is about 1 inch
from the lower edge of the glass. If more than
Ys inch either way remove the dust cap and
adjust by screws.

High speed adjustment. The high speed is
regulated by the lock nut LN on top of the
auxiliary air valve. As it is raised or lowered
it determines the point at which the auxiliary
needle valve ANV will be brought into play.
To lock nut LN should be about 3-32 of an inch
above the lever L for normal adjustment, but
this distance can be increased or decreased to
suit the motor.

To find primary nozzle size. If the mixture
is too rich on low speed after adjustments are
made according to instructions, take out the
plug P and remove the nozzle PN with a screw-

196

The Automobile Handbook

driver. Insert smaller nozzle (59 is smaller
than 58). If the mixture is too lean on low
speed a larger nozzle should be inserted. If
the engine misses on low speed it may be caused
by an air leak, and all the joints between the
carburetor and the motor should be examined
before a large nozzle is inserted.

Fig. 84
Stromberg Carburetor, Model "G"

Instructions for type G. Type G, Pig. 84,
is a non- water- jacketed model furnished in
either single or double jet according to motor
requirements.

Air adjustments. There are only two adjust-
ments that ever need attention, A, the low speed
nut, and B, the high speed nut.

With the motor at rest, set the high speed nut
B so there is at least 1-16 of an inch clearance
between the spring G and the nut X above it.
This is imperative.

The Automobile Handbook 197

Set the low speed nut A so the air valve E is
seated lightly. Do not adjust carburetor until
motor is thoroughly warmed up. When motor
is warm and with spark retarded adjust nut
A up or down until motor runs smoothly at low
speed. To determine proper adjustment open
the air valve with finger by depressing X
slightly. If, when so doing, motor speeds up
noticeably it indicates too rich a mixture and
A should be turned down notch by notch. If,
on the other hand, motor dies suddenly when
slightly opening the air valve it indicates too
lean a mixture and A should be turned up until
this is overcome.

Once properly set for idling do not change
this adjustment when making the high speed
adjustment.

Advance the spark at the normal position and
open the throttle gradually. If motor back-
fires through the carburetor it is positive in-
dication of too lean a mixture and nut B should
be turned up notch by notch until this is over-
come.

If mixture is too rich, as indicated by loading
of the motor and heavy black smoke from the
exhaust, turn B down until motor operates
properly. A further test for the correct mix-
ture at high speed can be made by depressing
the air valve when the motor is running at this
speed. If when so doing motor speeds up it
indicates too rich a mixture.

Turning either adjusting nut up means a

198 The Automobile Handbook

richer mixture or more gas. Down means a
leaner mixture or more air. To get highest effi-
ciency from this carburetor, hot air equipment
should be used.

Double jet type. If, after following the in-
structions given below, and with the motor run-
ning idle at low speed, the air valve E remains
tightly seated, it indicates too small a primary
nozzle C, and a larger one should be substi-
tuted. If with the proper adjustment, and after
stopping the engine, the air valve hangs off its
seat the primary nozzle is too large and a
smaller one should be used. To change the pri-
mary nozzle remove the petcock, insert a narrow
screwdriver and unscrew the nozzle.

If the mixture at low speed is correct, but in
order to get the proper high speed adjustment
it is necessary to turn the nut B up so far that
the spring 6 is in contact with X above it, after
the engine has been stopped, it indicates that
the auxiliary nozzle J is too small and a larger
one should be used. If it is necessary, in order
to get the proper high speed adjustment, to turn
the nut B down so that there is more than %
inch clearance between G and X when the en-
gine is idle, it indicates too large an auxiliary
nozzle and a smaller one should be used.

Instructions for types H and HA. There are
only two adjustments on this carburetor. Fig.
85. A, the low speed, and B for high speed.
A is a needle valve, seating in an open nozzle,
the opening of which is usually two sizes larger

The Automobile Handbook

199

than is ordinarily necessary, and which per-
mits an increase in gasoline flow to that extent
or allows a complete closing. The high speed
adjustment controls the flow of gasoline for
high speeds by regulating the time at which the
secondary needle valve begins to open.

Fig.

Stromberg Carburetor, Models "H" and "HA"
To adjust, set the high speed nut B so that
there is at least 1-32 of an inch clearance be-
tween it and the needle valve cap above it at
X when the air valve E is on its seat. The
needle valve does not begin to open until B
comes into contact with X. Before starting the
engine be sure that the rocker arm of the dash
adjustment on the carburetor is not in contact
with the collar above it at Z when the steering
post button is all the way down.

To start the engine, pull the steering post
oentrol to its highest position, thus producing a

200 The Automobile Handbook

rich mixture. In cold weather it may also be
necessary to close the air supply in the hot air
horn by means of a rod connected to R, This
should be again opened as soon as the engine
starts. As the engine warms up, gradually
lower the steering post control and make sure
that it is at its lowest position before commenc-
ing to adjust the carburetor.

Pig. 86
Stromberg Carburetor, Model "K"

The mixture at low speed is controlled by the
needle valve A. If too rich is indicated, by the
engine "rolling" or "loading," turn A up or
an fi -clockwise. If the mixture is not rich
enough, turn A down or clockwise. To adjust
high speed, advance the spark and open the
throttle. If the mixture is not rich enoi:^h
at high speeds, turn B up or anti-cloekwiae,
and if the mixture is too rich turn B down or
clockwise.

instructions for types K and SO. The nut

The Automobile Handbook 201

A is the only adjustment on this carburetor,
Fig. 86. The stem of this nut supports the
lower end of a spring that controls the air
valve. This air valve opens downward into the
air chamber. Turning the nut A clockwise or
down tightens this spring, admitting less air
and producing a richer mixture. Turning A
in the opposite direction or anti-clockwise pro-
duces a leaner mixture.

Before starting the engine turn A anti-clock-
wise until a point is reached where, when lift-
ihg or pulling up on A, a decided click is
heard. This is the air valve coming in contact
with its seat. Then turn A clockwise or down
until the click is no longer obtained. This turn-
ing should be a notch at a time, and when the
click can not be heard, turn two more notches
in the same direction. To start the engine,
raise the steering post control to its highest
position. Gradually lower the control as the
engine warms up, and make sure that this con-
trol is at its lowest position before starting to
adjust the carburetor. With the engine warm,
turn A up or down, notch by notch, until the
engine idles properly. It should not be neces-
sary to change the initial setting more than a
few notches.

The high speed mixture can only be affected
by changing the nozzle. If the high speed
mixture is too thin, so that slightly closing the
dash throttle valve R causes an increase of en-
gine speed, a larger nozzle should be used. If

The Automobile Handbook

the high speed mixture is too rich hae a smaUer
nozzle. The nozzle size furnished is baaed od
18 inches of hot air tubing. If this tubing ia

Pig. 87

Zenith Carburetor, Model "O". B, Float Control
Lever. CI, Dust Cap. D, Strainer Body, Dl,
Wire Gauze. E, Gasoline Channel. F, Float.
G, Main Jet. Gl, Needle Valve. G2, Float
Control Collar, I, Gas Well Opening. H, Sec-
ondary Nozzle. J. Gasoline Well. K, Gasoline
Passage. L, Drain Plug. N, Idling Adjust-
ment. S, Float Valve Opening. T, Throttle.
X, Choke Tube.

The Automobile Handbook 203

more than 24 inches long, one size smaller noz-
zle can probably be used, while if the tubing
is less than 10 inches long one size larger may
be required.

Zenfth Carburetor, Model 0. This carbure-
tor, a cross-section of which is shown in Fig.
87, consists of a float chamber, a carbureting
chamber, a system of nozzle and air passages
and a hot air sleeve.

Gasoline from the tank enters the strainer
body D, passes through the wire gauge Dl, and
enters the float chamber through the valve seat
S. As soon as the gasoline reaches a predeter-
mined height in the float chamber the metal
float F, acting through the levers B and collar
(t2, closes the needle valve Gl on its seat. To
see if there is any gasoline in the carburetor
remove dust cap CI. If the needle valve can be
depressed with the finger there is no gasoline in
the carburetor. From the float chamber to the
iQotor gasoline flows through three different
channels in various quantities and proportions
giccording to the speed of the motor and degree
i»f throttle opening. With the throttle fully
i)pen, most of the gasoline flows through the
channel E and main jet G. Some flows through
compensator I, then through K to the cap jet
H, which surrounds the main jet. The main
jet and cap jet work together and their com-
bination furnishes the mixture required for
various engine speeds. At slow speed when the
throttle T is nearly closed they give but little

204 The Automobile Handbook

or no gasoline, but, as there is considerable suc-
tion on the edge of the butterfly the tube J,
terminating in a hole near the edge of the but-
terfly, picks up gasoline, which is measured out
by a small hole at the top of the priming plug.
The well over compensator I is open to the air
through two holes, one of which is indicated be-
low the priming plug in the illustration. These
air openings are important.

The hot air sleeve is provided with an air
strangler actuated by a lever and having
a coiled spring to bring it back to the open posi-
tion. The flexible hot air tubing is attached to
this sleeve and feeds the carburetor with air
that has been heated by contact with the ex-
haust pipe.

To start the engine open the throttle a little
way. There will be a strong suction on the tube
J which will raise the gasoline and thus prime
the motor. The only adjustment that may be
us(»ful is the slow speed adjustment, which is
obtaiiK'd by the screw 0. Tightening this screw
rcsti'icts the air entrance to the slow speed noz-
zl(\ priviiig a richer mixture.

Ft is (essential that none of the parts shall be
tampered with, or the size of the jets altered by
reamiiifi: or hammering. These jets are tested
for actual flow of gasoline and brought to a
standard. The nominal size of the hole in hun-
dredths of a millimeter is stamped on the jet:
the higher the number, the larger hole.

Variables that can be modified for the initial

The Automobile Handbook 205

iietting of the carburetor: First, the choke tube
X. This choke tube is held in place by set
sjcrews and can be removed after taking apart
the throttle.

It is really an air nozzle, of such a stream
line shape that there will be no eddies in the
lir drawn through it.

For a 4 cylinder engine whose maximum speed
s 1,500 R. P. M., to obtain the choke number,
nultiply the bore in inches by five and add one
X) the result.

For 6 cylinder, take a choke one size larger
ip to 4^" bore and two sizes larger above 41/^"
jore.

If the engine is so built that it can turn up
;o 1,800 R. P. M., increase these results 8% ; up
;o 2,000 R. P. M., increase 16%; up to 2,500
El. P. M., increase 25%.

A choke tube too small will cause a loss of
jharge at high speed, the car will not attain its
proper speed.

A choke tube too large will lead to irregularl-
;ies when slowing down and picking up.

Second — Main Jet C. The effect of this jet
s most marked at high speed, 1,400 R. P. M.

Third — Compensating Jet I. This jet, which
jompounds with the main jet, exerts its maxi-
num influence at lower speeds, 600 R. P. M.,
tnd in picking up.

Fourth — Secondary Well P. This regulates
he amount of gasoline used when idling.

206 The Automobile Handbook

Change Speed Crearing.

The means provided for securing different
ratios of speed between the engine and road
wheels of the car is oftentimes called the
transmission. Strictly speaking, the transmis-
sion system includes all the parts between en-
gine and wheels; the clutch, universals and
roar axle parts, as well as the mechanism that
allows various forward speeds and the reverse.
The Change Speed Gear takes various forms:
planetary, friction, sliding gear and magnetic,
each being described.

Change Speed Gears. When a gasoline en-
gine is loaded above a certain limit it slows
down, and the intervals of time between ex-
plosions in each cylinder become so far apart
that the enjrine begins to labor, and will finally
stop altoK^'ther, unless some means is provided
wherc^by the ri^volutions of the engine may be
increased without increasing the number of
revolutions of the driven shaft, or car axle.
This is a(*(*()nii)lished by means of the changre
spcM'd ^ear, of which there are two classes, viz.,
those in which an infinite series of variations
in si)eed ratio is x>ossible, and those in which
only a comparatively small number of step-by-
st(»p ratios can be utilized. In the first class
are several styles of belt and friction disc
drives, while in the second class are the change
spoed gears proper, namely, sliding gears, indi-
vidual clutch gears, and planetary gears.

^^^1+ and friction drives constitute the only

Tk£ Automobile Handbook

207

Lctical forms of change speed devices iu
ieh variation from the highest to the lowest
ed may be possible. In other change speed
lFs the ratio is changed by passing from one
another in a series of definite steps.

•'riction Drive. One of the moat simple
thods of changing the speed ratio between
motor and the driven shaft is the friction
TB, wbich in its simplest form consists of
t discs at right angles to each other, see Pig.

208 The Automobile Handbook

88, in which b is the fly wheel, the exterior sur-
face of which is made a true plane, and usually
covered with a special friction metal. A hori-
zontal shaft located crosswise of the car body
carries a friction pulley c, in close proximity to
the surface of the fly wheel b.

Friction pulley c while secured from turning
on shaft, may at the same time be shifted along
at the will of the operator, and thus be
brought in contact with any portion of the sur-
face of the flywheel, from its center to its outer
edge. The shaft also carries on its outer ends,
the sprocket wheels which drive chains e and
f, by means of which the power is transmitted
to the drivers. In this device if the friction pul-
ley c be brought in contact with the exact cen-
ter of fly wheel b, no motion will be imparted
to c, but if it be moved outward from the
center of the flywheel it will revolve, the num-
ber of revolutions it makes being governed by
its distance from the center. The maximum
speed is attained by friction pulley c when it is
brought into contact with the surface of the fly
wheel near the periphery of the latter. All po-
sitions of friction pulley c upon one side of the
center of fly wheel b impart a forward motion
to the car, and all those on the other side of the
center impart a reverse, or backing motion. The
traversing movement of pulley c along its shaft
is usually produced by a hand lever provided
with a notched quadrant, whereby the pulley is
held at all times in some one of the many posi-

The Automobile Handbook 209

tions giving graduations of speed. The method
usually employed for making and breaking con-
tact between the friction pulley, and flywheel
face, consists in mounting the bearings of the
cross, or countershaft in swinging brackets. An-
other method is to mount these bearings in ec-
centric housings, a slight rotation of which in
the bearing brackets will cause the shaft and
with it the pulley to approach, or recede from
the face of flywheel b. The movement of the
shaft toward, or away from the flywheel is pro-
duced by a ratchet retained pedal through a
reducing linkage, which multiplies the foot
pressure.

Double Disk Friction Drive. The limitation
of the single disc and wheel to small power, and
light loads, has led to the development of the
double disc, double wheel type of friction gear
illustrated in Fig. 89.

The engine shaft is extended, and carries two
disc fly wheels A and B, while friction pulleys
C and D are each carried upon one half of
the cross shaft which is divided at its center.
Friction pulleys C and D are made to slide
along the shafts H and F, and are controlled
by a common sliding mechanism, so that they
always bear upon points of discs A and B, hav^
ing the same velocities. Driving contact is ef-
fected by swinging shafts H and F in a hori-
zontal plane, and it is obvious that if one of the
pulleys, D for instance, is pressed against the
face of A, it will revolve in one direction, while

210

The Automobile Handbook

if brought to bear on B it will revolve in t
opposite direction, thus providing for a ^
ahead, or a back-up motion being imparted
either friction wheel at will, dependent up
whether it is in contact with the forward, or 1

rearward disc. It is also evident that if o

of the wheels, say D, is pressed against A, ai

^^'^ -^ther wheel C is also pressed agai&st

■ihafts will rotate in opposite directioi

^ A of the common angular velocity of t

The Automobile Randboolp 211

\vheels and their shafts to that of the discs is
in proportion to their distance from the center
of the discs. Sprockets upon the extremities of
shaft H and F drive the road wheels by chains,
and sometimes no differential is employed,
power being shut off when turning comers, or,
if not, the inevitable slip is divided between the
frictional contacts, and the contacts of the tires
with the road. A differential may be mounted
in either shaft H or F at will.

Instead of the two shafts H and F being sep-
arate, they may be joined to form a continuous
shaft and pivoted in the center. The shaft as
a whole is capable of being slightly swung in a
horizontal plane about its center, so as to bring
friction wheel D in contact with one disc, and
friction wheel C in contact with the other, thus
producing either the forward or reverse drive.
In this case a single sprocket is carried by the
shaft and drives a live rear axle.

Friction Drives — Materials For. In fric-
tion drives, one of the surfaces in contact is
generally a metal, while the other surface is
composed of some kind of organic material, of
a slightly yielding or conforming nature. Cast
iron with cork inserts may be used for the me-
tallic surface, the^ cork inserts serving to in-
crease the co-efficient of friction, besides absorb-
ing any oil that may accidently reach the sur-
faces. Aluminum is no doubt the best material
for the metallic surface, on account of its plastic
nature. Copper also possesses similar proper-
ties. For the non-metallic surface, leather is
good so long as oil is kept from accumulating

212 The Automobile Handbook

on it, but its co-efficient drops rapidly as soon
as oil gets between the contact surfaces.

Some kind of vegetable fibre, made into a
paper or mill board, seems to be the preferred
material, and it is comomn to treat such paper
with a tarry composition, which tends to raise
the co-efficient of friction, as well as to render
its value more nearly constant under the influ-
ence of water and oil.

The non-metallic friction face is the one worn
out in service, or at least it wears the more rap-
idly. This part of the combination, though of
limited life, can be renewed at a comparatively
small expense, and it fails only after giving due
notice. It is the practice to make the disc face
metallic, and the friction wheel rim non-metal-
lic. Great care should be exercised in starting
the car, as at such times the disc is liable to
slip at speed upon the rim of the friction wheel
which is then either stationary or revolving
very slowly, and flat spots may very easily be
worn upon its surface.

The Planetary Change Speed Gear. This
system of transmitting the power at various
speeds comprises a high-speed connection for
the direct drive, and an arrangement of gears
that reduces or reverses the 'motion when one
or another drum on which these gears or pin-
ions are mounted is held stationary. Most
planetary systems give only two forwar(f^speeds
and the reverse, but in some instances they are
made to give three forward speeds. They are

The Automobile Uar^dbook

213

used chiefly on small automobiles, or runabouts ;
but when cheapness of construction is an object
they are sometimes employed on touring cars.
In Fig. 90 is shown one form of planetary
system. The gear a is tie only one keyed to

the engine shaft b. The gears c, d and e all
mesh with the gear a, and are made long enough
to est<Bd beyond a and mesh with the gears
f, g and h in pairs. The last three gears in
turn extend beyond the gears c, d B,r<<^ e, and

214 The Automobile Handbook

mesh with the gear i, which is keyed to a sleeve
connected to the drum j. The gears c, d, e, f,
g and h turn on pins fastened to the drum k,
but only the gears c, d and e mesh with a, and
only f, g and h mesh with the gear i which
turns loosely on the shaft b. The internal gear
1 meshes only with the gears c, d and e, and
is rigidly connected, to the sprocket m that
drives the automobile. The cover n is attached
to the face of the drum k by means of screws,
thus forming an oil reservoir thai keeps the
gears well lubricated when the automobile is
running. There are separate brake bands
around the drums j and k, and a friction disc
keyed to the shaft just outside of the drum j.

When the friction disc is pressed against the
drum j, the gear is held so that it must turn
with the shaft; consequently, the entire me-
chanism is locked together and the sprocket m
turns at its highest forward speed. li now the
friction disc is released and the brake band
around the drum j is applied so as to hold it
from turning, then the gear a turns the gears
c, d and e, causing them to turn the gears f,
g and h; but, as the gear i is held stationary
with the drum j, the gears f, g and h, and also
the drum k, to which they are attached, must
revolve around the gear i in the same direction
as the shaft turns, but more slowly. The gears
c, d and e turn on pins that are fastened to the
drum k; consequently, they revolve with it as
they turn on their axes and thus cause the in-

The Automobile Handbook

temai gear 1 and the sprocket m to turn in the
same direction as the shaft. This gives the slow
forward speed.

"When the drum j is released, and the drum k
is held by a brake band, the gears c, d and e
are caused to turn on their pins, and conse-
quently drive the internal gear I in a direction

The Automobile Handbook

opposite to that of the engine shaft, driving 1
autonioliile backwards. "When the brake bai
and friction disc are all free from the drui
tlie gears turn idly, and if the engine is rmrni:
no motion is transmitted to the sprocket a
the automobile stands still.

A form of change speed gearing that is
nse on a large majority of cars is that kno
as tlic sliding gear. All sliding gear tra

The Automobile Hlmdbook 217

missions consist of two principal shafts lying
parallel to each other and placed one above the
other or side by side. Each shaft carries a

series of gears, those on one shaft being per-
manently fastened against lengthwise move-
ment, while those on the other shaft are capable
of being moved along the shaft while turning
with it. This latter set of gears is built with

either a square or key-waved hub and the shaft
on which the set slides is made square or with

spline keys to correspond. The gears on the

other shaft are made of such sizes that when

the sliding members are moved they come into

mesh with the gears on the other shaft so that

when together they form pairs, that is to say,

when a gear on one shaft is in mesh with one

on the other shaft it is impossible to cause

any other gears to mesh at the same time.

The gears are graduated in size so that the
several pairs or combinations that may be
formed vary in ratio, and in this way it is pos-
sible to obtain different degrees of speed reduc-
tions between the two shafts and therefore
between the engine and road wheels.

In forms of construction that use the two
shafts exactly as described in the previous para-
graphs, and in which one shaft is connected
through the clutch to the engine and the other
one through the drive parts to the rear wheels,
the series of sliding gears is made with all of
the gears fastened together so that there can be
no relative motion between them, and in this

218 The Automobile Handbook

Selective Sliding Cliange Speed Gears

The AutomobUe Handbook 219

case the entire sliding member is moved bodily
along the shaft. This particular form is known
as a progressive sliding gear. It is necessary,
with this type of construction, to pass from one
ratio to another in the same order for each
operation, and if it is desired to pass from the
extreme low ratio to the highest ratio, it is nec-

■ Fig. 94

Selective Sliding Gear With Disc Clutch In a
Unit Power Plant. A. Clutch Shaft. B, Clutch
Shaft Gear, C, Countershaft Gear. D, Second
Speed Gear. E, Low Speed Countershaft Gear.
P, Second Speed Sliding Gear. G, Low and Re-
verse Sliding Gear. H, Sliding Gear Shaft.
essary to pass through all intermediate ratios.
The progressive form of transmission is no
longer fitted to cars and an extended descrip-
tion is not considered necessary.

220 The Automobile Handbook

The type of sliding gear transmission that
is most popular is called the selective sliding
gear and with the exception of some important
modifications is similar in operation and con-
struction to the progressive type already de-
scribed. Selective sliding gears are shown in
Figs. 92 to 97 and the following description
will apply more or less to all of them although
the form shown in Fig. 94 is specifically cov-
ered. It will be noted that the clutch is at the
left hand end of the illustration, and through
this clutch the power of the engine is trans-
mitted to the shaft marked A. At the right
hand end of the shaft A is carried a gear B,
and this gear is in mesh with the gear C on
the lower shaft of the transmission, it will there-
fore be seen that whenever the clutch causes
shaft A to revolve, gears B and C will also turn,
and inasmuch as C is fastened solidly to the
lower shaft of the transmission, this lower shaft
will turn whenever the engine is running and
the clutch engaged. The upper shaft in the
transmission marked H is not made in one piece
with shaft A, but its left hand end is made of
a diameter suflSciently small to fit into a recess
in the shaft A and in the hub of the gear B.
This construction simply provides a bearing for
one end of the shaft H so that it may revolve
independently of shaft A. Shaft H is formed
with four longitudinal keys integral, and on
this shaft are mounted the gears F and G with
their hubs formed with keyways to engage

The Automobile Handbook

221

the ke7B on shaft H. This constimction allows
the gears F and G to be moved lengthwise while
turning with the shaft. Qeata D and F are
made of such diameter that when P is moved
to the right it meshes with D and gears E and
G will mesh when G is moved to the left. The
right hand end of shaft H is fastened to the
universal joint that leads to the rear axle.

Ftg. 95
Sliding Gear Set for Separate Mounting
The operation is as follows: "With the en-
gine runnine and the clutch engaged, power
is transmitted through gears B and C to the
lower shaft of the transmission, and iniismueh
as gear C is larger than B, the lower shaft
will run at a lower rate of speed than the clutch
shaft. If now the gear G be caused to mesh
with E, the shaft H will be revolved but at a
still lower rate of speed than the bottom shaft.

The Automobile Handbook

and inaBmuch as H drives the rear axle it will
be seen that the meehanistn has given a positive
drive at a speed much below that of the engioe.

Fig. 96

Heavy Duty Selective Sliding Gear for Rear Axle

Mounting

Wht'ii it is desired to secure a higher speed

of the car relative to that of the engine, gears

The Automobile Handbook 223

G and E are withdrawn from each other and
gear F is moved into engagement with D. It
will be noted that gears D and F are approxi-
mately the same size, and the upper shaft will
then turn at a speed very nearly the same as
that of the bottom shaft, but still less than
the speed of the engine. This position is known
as second speed or intermediate speed.

When it is desired to secure a still higher

ration of speed it is done by moving gears D and
F out of engagement and then moving F to

the left. Gear F carries one-half of a jaw, or

toothed clutch, and gear B carries the other

half of this same clutch. It will thus be seen

that when F and B are together the clutch will

be engaged and shaft A will drive shaft H at

the same speed at which A is revolving. This

provides high speed or direct drive.

When it is desired to reverse the direction of
motion of the car, gear G is moved into engage-
ment with an idler gear that is not shown, and
this idler gear is driven through another one
on the bottom shaft of the transmission. The
idler gear being interposed between the upper
and lower transmission shaft gears causes the

upper shaft to reverse its previous direction
of motion.

Certain variations of selective sliding gears
are in use, one of which is shown in Fig.
97. In this particular form the spur gears
remain in mesh at all times, but neither set
is keyed to its shaft. Between the gears are

224 The AutoTnoiile Handbook

mounted jaw dutches, and these clutches are
keyed to the shaft. In place of movii^ th|
gears into or out of engagement, the jaw
clutches are moved, and depending on which
clutch is moved and which way it is moved,

Fig, 97

Individual Jaw Clutch Sliding Gear Set
the several sets of gears may be successive^
used, providing speed ratios similar to those
in other forms of selective sliding gears.

Magnetic Truumiasion.
The difference between a car with magnetic
transmission and other gasoline cars lies only
in this tranamission. There is no change in the
engine or its operation. There is no change
in the driving parts, save as regards their con-
nection with the power. The parts omitted
are the clutch and the clutch pedal, gears and
shifting lever, flywheel, starter and lighting sya-
tern, this one transmission unit taking the place
of all. There is no mechanical connection be-
tween the engine and the driving shaft. This

The AutomolUe Handbook 22b

226 The Automobile Handbook

control also embodies an electric brake, and an
automatic electric sprag, which absolutely pre-
vents the car backing down hill, even though
the motor is stalled. Should the engine be
stalled on a hill, the car can be held without
use of the brakes by simply moving this con-
trol lever into high speed position.

The power is never disconnected from the
driving wheels of the car from the moment of
starting up to the highest speed.

The electrical apparatus consists of two units,
Fig. 98, contained in a one-piece construc-
tion : the one nearest to the engine has its mag-
netic field pieces keyed to the engine crank-
shaft and acts as a flywheel to the engine. Its
armature is mounted on the propeller or drive
shaft, hence it will be seen that both these parts
can revolve. The second unit of the apparatus
has stationary magnetic fields and its armature,
as in the first ease, is mounted on the propeller
shaft. The first unit becomes in turn a
dynamo, magnetic clutch and a motor, the sec-
ond unit, a motor and d>Tiamo.

A eontroller, with resistance coils internally
contained, is bolted to the chassis frame for-
ward of the dash, alongside of the engine, and
is operated by a lever on the steering wheel
through a small gearing at the bottom end of
the steering column.

By placing the control lever in the position
''cranking," a battery is connected through
the first unit, which in this instance becomes

The Automobile Handbook

227

a motor, and once the engine is cranked, the
lever can be placed in the ** neutral" position
until ready to start the car.

On moving the control lever to the first po-
sition, turning effort is produced by weak-
ening, with a shunt resistance, the field of
the first unit, which becomes a dynamo, and

B C

Fig. 99
Principle of the Magnetic Transmission: A, En-
gine Cranl^shaft. B, Revolving Field. C, Sta-
tionary Field. D, Front Armature. E, Rear
Armature. F, Propellor Shaft.

the current generated, due to the electrical
slip between the magnetic fields and the arma-
ture, is fed to the second unit, which, acting
as a motor, produces a powerful starting torque.
At the same time the pull of the magnetic fields
of the first unit acts as a magnetic drag on its
armature, and thus two forces assist in rotat-
ing the propeller shaft, which, through the bevel
drive, communicates power to the road wheels.

The second position of the control lever cuts
the resistance out of the first unit (dynamo)
field and shunts through a high resistance some
of the field current in the second unit (motor),
thereby increasing the speed of the car.

228 The Automobile Handbook

In the third, fourth and fifth control lever
positions, the second unit (motor) field is suc-
cessively weakened until in the sixth control
lever position, the field current is almost en-
tirely shunted, so that previous to placing the
control lever in the seventh (and last) position,
the second unit is practically of itself not do-
ing any work, apart from the fact that there
is very little slippage between the first unit
(dynamo) field and armature, resulting in gen-
erating of but small current. In other words,
the drive shaft is being carried around almost
entirely by the magnetic drag of the first unit's
field on its armature. It will hence be seen that
there is an electrical balance in effect through-
out the entire sequence of operations.

On placing the control lever in the seventh
position, the first unit becomes what may be
termed a ** magnetic clutch,'* the armature
and field are closed-circuited, and an almost
negligible slip only is required to generate suf-
ficient current to enable the field to drag its
armature around with it.

The second unit with the control lever in
high speed position becomes a generator, and
when the car is running, charges the lighting
and starting battery with a predetermined
charge.

From this point on the entire control is
brought a])out by accelerating or decelerating
the gas engine, the armature of the first unit
follows its magnetic field promptly, generating

The Automobile Handbook 229

of its own accord whenever necessary more cur-
rent and hence getting more magnetic drag to
bring it up to the same speed as the magnetic
fields. Thus, so long as the control lever
is in any position other than neutral on ac-
celerating, an increase of speed is obtained,
but on decelerating, the car coasts just like an
ordinary car with the clutch released. This is
brought about by the armature of the first unit
traveling faster than the fields, and thus not
generating any current until such a time as
the car comes back to the speed, where the arm-
ature of the first unit is traveling at the same
or slightly lower speed than the field pieces
or the engine, when again current is generated
and the drive taken up as before.

Should excessive grades be encountered where
extra torque may be desired, the placing of the
control lever in a lower position will give the
desired result, and naturally by increasing the
engine speed with the control lever in a lower
position than high, more current will be gener-
ated, due to the extra electrical slip, and thus
give added torque.

At neutral position the maximum electrical
braking effect is obtained. Here the first unit is
open-circuited and the second unit closed-cir-
cuited and the magnetic braking reaction brakes
the car to 10 miles per hour, below which speed
the armature does not revolve within the motor
field fast enough to create the braking effect,
thus automatically holding the car on a grade at
about the above speed.

230 The Automobile Handbook

Chassis. The word chassis since its adoption
into the English language, is taken to mean the
frame, springs,* wheels, transmission and in fact
all mechanism except the automobile body. In
its original French it does not mean all this, but
is strictly restricted to mean the frame, or the
frame and springs.

Chauffeur. This term when literally trans-
lated means the stoker or fireman of a boiler.
The use of the word has been extended to the
operator of a motor car, but does not usually re-
fer to the paid driver, who is generally known
as the mechanician or mechanic.

Clutch. Clutches may be classified as fol-
lows : a, cone ; b, disc ; c, band ; cone clutches
may, in turn, be subdivided as follows : a, metal
to metal; b, leather faced; c, cork insert; while
disc type may be classed as: a, leather faced;
b, multiple disc; c, cork insert; and band
clutches may be put down as of the a, constrict-
ing, b, spiral, or c, expanding types. Clutches,
of whatever type or class, have but one prime
object, i.e., to enable the operator to start and
stop the car without having to stop the motor.
There is a secondary consideration, if we take
into account the fact that it is convenient to be
able to slip the clutch, on occasion. Some types
lend themselves to this secondary purpose with
greater facility than others, and it is also true
that some clutches are most easy of application,
all things considered.

As clutches are at present designed, the ques-
tion is, can slipping be tolerated? or, can

The Automobile Handbook 231

clutches be slipped to control the speed of a
car? It is believed not. The average clutch
has very little of the character of the average
braking system, and when it comes to brakes
they do not last so long that it is desirable to
wear them out sooner than they will naturally
need replacement. In other words, it seems
quite out of the question to consider the
clutches of today as suitable for the double pur-
pose of clutching -and speed controlling, by way
of slipping the clutch at will. It is not uncom-
mon to hear autoists talking of the multiple
disc clutch as one that undergoes little or no
deterioration as a result of continuous slipping
under variations of load.

They seem to think that the large surface ex-
posed, especially in view of the fact that the
discs are submerged in oil, will prevent damage
if the clutch is caused to slip. They forget that
the discs are thin, and also that they are loose
on the splines, keys, or feathers that prevent
the discs from rotating. No member keyed onto
a shaft will stand much abuse. This is espfs-
cially so, if the member has but little bearing
surface on the key. Even a considerable num-
ber of such members working in unison will
fail to stand up under the work because the
joint is not firm. Lost motion is bound to re-
sult in more lost motion in a short while, and
in a multiple disc clutch the discs soon fray out
and interfere with each other, and with the
clutching functions, within a space of time so

232

The Automobile Handbook

short as to surprise even those most experi-
enced in the use of this type.

Band Clutch. A band, or friction ring,
clutch, is shown in Fig. 100. The wheel which
is connected to one of the shafts is shown at a,
and the band, or ring which is connected to the
other shaft and which is made in two parts, is
shown at b and c. At d and e are cufved arms

Fig. 100

pivoted at f and g. The links h and i connect
these curved arms to the parts b and c of the
band. By means of a fork, and tapered sleeve,
not showTi, the ends j and k of the arms are
forced apart when the clutch is brought into
use. This throws toward the shaft the ends 1
and m of the levers d and e, and brings the two
parts b and c of the clutch ring in contact with

The Automobile Handbook 233

tile friction or driving surface of the wheel a,
which is thereby forced to turn with the driving
shaft. The band clutch has had many expo-
nents in the motor car art, but is open to cen-
trifugal effects to such an extent that it re-
quires considerable ingenuity to overcome trou-
bles arising therefrom. At high engine speeds
the operating levers have been so arranged as
to lower tb'j normal expanding presstire.

Fig. 101
Cone Clutch. There are a number of modi-
fications of this type of clutch, the general prin-
ciples of which are illustrated in Pig. 101, The
flywheel a is secured to the shaft b by means
of bolts through the web of the wheel. At c is
an expansion ring into which the friction cone
d fits. The helical spring e holds the cone
against the expansion ring with the required

The Automobile Handbook

amount of force. At f is a ball bearing^ that
takes the end thrust when the cone is pulled
away from the expansion ring.

The arms g are coupled to the shaft that turns
with the friction cone. Ordinarily the two parts
of the clutch are held together by the pressure
of the spring, and when it is desired to discon-
nect the cone, a foot pedal is forced down so
as to act on a fork and sleeve and pull the cone

Fig. 102
away from the expansion ring. When the pedal
is released, spring e forces the clutch into action
again.

Fig. 102 is a sectional view of a form of
leather faced cone clutch in which the male part
of the cone moves axially toward the engine.
Fig. 103 shows a clutch constructed on the
same principle, but in place of having one
strong sctuatinc spring surrounding the axis,
it has three weaker spiral springs near the pe-

The Automobile Handbook 235

riphery of the male member. Fig. 104 is a verti-
cal section of a clutch suitable for a 50 H. P.
ear. The cone angle is 13 degrees, and the di-
ameter 16 inches, with a total frictional area of
128 square inches, the axial pressure resulting
from the spring being 375 lbs. A small spiral
plunger spring A under the leather face B
causes it to pick up the load mpre quietly and
smoothly. Fig. 105 illustrates an early form
of clutch intended for a ear of about 20 H. P.
One form of toggle joint is also shown at A.

Fig. 103

This clutch also has multi-springs for creating
the proper frictional contact, and a peculiar
form of spring application simple in the ex-
treme.' A multi-cone clutch is shown in section
in Fig. 106. Its action is as follows: When the
clutch engages, the smallest cone seizes first,
commences to revolve and subjects the spiral
springs between the next two clutches to tor-
sional movement, which draws them together
and brings the two outer eones into action ; the
idea being that the small clutch shall slip, tend

The Automobile Handbook

to accelerate the car, that the medium clutch
shall behave id a similar manner and that when
the large clutch comes into play the three com-
bined pick up the load and move the car.
The so-called inverted cone is well illustrated

in fifriiro 107. The reversed cone is contained
in an extension A, bnilt onto the flywheel B.
When the cone? is diseiiKaKed it moves toward
the enpine, exactly revcrsiiiK the aetion of the
foregoing type. This clutch has its adherents.

The Automobile Handbook 237

and it is a good one, diifering very slightly, if
properly assembled, in its efficiency from the
direct-acting cone. It may be kept free from
dirt and oil much more perfectly than in the
other form.

Disk Clutch. A clutch of the multiple-disc
type IS show n in Fig 108 A two arm spider
a, kejed U> the shaft b, serves to hold m place a
number of metal discs c, between which are
other metal plates d held on the sleeve e by
means of a key f The sleeve e is in turn keyed

Fig. loa

to the shaft g, and to it is screwed a ring h
having three pairs of lugs carrying three levers i,
with rollers j at their outer ends, as shown. The
other ends of the three levers press against the
plate k when the clutch is engaged by an in-
ward movement of the collar 1, plate k being
free to move along the key f. Discs c are free
to move longitudinally on the arms of the spi-
der a, and also on sleeve e, around which they
rotate when the clutch is out of engagement;
but the arms of the spider, fitting into slots in
the discs, cause them to rotate with the shaft b.

238

The Automobile Handbook

The plates d are free to move longitudinally on
the key f in the sleeve e ; and since the sleeve is
keyed to the shaft g, it is evident that, when
in engagement with the discs c, the plates d
must cause the shaft g to turn with the shaft b.
The discs c and plates d run in an oil bath,

Fig. 107
obviating wear of the plates and discs. These
are brought together forcibly by throwing the
cone faced end of the collitr 1 against the rollers
j, thereby causing the ends of the three levers i
to press the plates and discs together with suf-
ficient force to cause the shafts b and g to rotate
as one shaft.

The Automobile Handbook

239

PiVE-PLATE Clutch. In the matter of the num-
ber of plates in the disc clutch there is no agree-
ment between designers. Some use a very large
number of thin plates, as many as fifty or sixty,
and others use a very small number, as few as
six or eight ; in fact, it may be said that the sin-
gle disc clutch, which has only two frictional

surfaces, is the lower limit. One arrangement
which uses five plates is shown in Fig, 108. The
diameter of the clutch is somewhat smaller
than that of the single or three-plate types, but
its diameter must be quite large in order to
transmit considerable horse power.

Clutches are made with various numbers of
plates, from three to more than sixty, depending
on the work required and the size and material

240 The Automobile Handbook

of which the plates are made. Plate materials
include hardened steel for both members, steel
and bronze, steel with cork inserts, and steel
covered with some friction material similar to
brake lining.

Disc clutches using steel to steel are operated
in a bath of oil. Those using bronze and steel
may or may not operate in oil. As a general
rule, clutches that are not enclosed are fitted
with cork or an asbestos composition as the fric-
tion material. However, either of the forms just
mentioned operate satisfactorily in an oil bath,
and it is, therefore, simply a question of choice
with the designer. Unenclosed clutches are
called ** dry-plate clutches.'*

Clutch Troubles. One of the greatest
sources of trouble for the novice liei^ .in the
clutch. This may be just right, it may' be slip-
ping, or it may be what is called fierce. The sec-
ond manifests itself in such pleasant situations
as climbing a hill when, with the engine run-
ning at its highest speed and the proper gear
engaged, the car starts to run backward instead
of .forward. Or on the level, with the engine
racing and the high gear in, no speed results.

The last condition shows itself in the sudden
jumping forward of the car when the clutch
has been lot in, or it may even be so severe as
to shear off the bevel driving gear when used
with studded non-skid tires or any form that
will not slip easily.

To repair the first, look at the leather, if this

The Automobile Handbook 241

is all in good shape with an apparently good
surface, but has lubricating oil on it, wash the
surface well with gasoline. It is not a bad idea
to roughen the surface of the leather a little
with a coarse file.

The harsh or fierce clutch is remedied by the
application of a proper oil for this purpose.
Castor oil is universally used and a good way is
to soak the complete clutch in it over night.
This will cure a case of harsh leather, but it
may be that the trouble is only a lack of adjust-
ment of spring tension. Usually there is an ad-
justing nut and a locking nut. Back off the
latter and make an adjustment. Then tighten
the lock nut to retain it. For the beginner, it
is better to adjust a little at a time and make
several successive jobs of it than to try to do
it all at once. But always adjust it as soon as
possible.

The leather of the ordinary cone clutch by
degrees acquires a sort of coarse surface glaze,
which may or may not represent actual charr-
ing of the leather, but is certainly due to the
slipping it experiences. A leather with its sur-
face so glazed has a very harsh action, since the
surface is so hard that it grips all at once. The
glazed surface will not absorb oil to any appre-
ciable extent, a fact which is easily seen on at-
tempting to dent the surface with a thumb nail
after giving the oil time to soak in. In this con-
dition the best thing to do is to put on a new
leather. Unless the angle of the cone is too

242 The Automobile Handbook

abrupt, a piece of ordinary belting will serve
the purpose, provided it is of uniform thickness
throughout. The belting may be soaked in
neatsfoot oil over night before applying, and
this will render it pliable enough to take the
shape of the cone. If the old leather is retained
in service it becomes almost essential to squirt
a little oil on it every day or two, as otherwise
it may take hold with such a jerk as to endan-
ger the transmissiou shafts. If the cone re-
leases by drawing backward, there are proba-
bly openings in the web of the cone through
which the spout of a squirt can may enter. Oil
squirted into the flywheel interior will then
quickly find its way to the clutch surface.
Sooner or later, however, the leather will be-
come glazed so smooth that it will not hold at
all, and it is then liable to slip and bum up
without warning. There are few things more
exasperating than a clutch which cannot be
made to. hold properly, particularly when the
car happens to be covering a bad stretch on
which every available bit of power that can be
transmitted to the rear wheels is necessary. The
use of emergency remedies under such circum-
stances most often leads to the necessity for
clutch repairs, as road dirt and grit are not the
best things possible for the leather facing, and
frequently no other friction producing com-
pound is to be had at the time.

Renewal of Leather on Cone Clutch. Re-
move the old leather by cutting off the rivets

The Automobile Handbook 243

on the underside, and driving the rivets through
to the outside. Keep the old leather and use
it as a pattern by which to cut the new piece.
It will be much better, however, to purchase
from the factory a new leather of the. proper
width and thickness. As a new leather will
have considerable **give," it must be stretched
tightly over the cone. First cut one end of the
leather square and fasten it to the cone with
two rivets. The other end should not be cut at
this stage of the work, but brought around to
meet the fastened end, and, after tightly
stretching it over the small end of the cone,
fasten it with a single rivet. Then force the
leather up onto the cone, drill out and counter-
sink the holes and rivet up securely. The only
knack in the operation is to keep the leather
tight that it may be a snug fit on the cone. A
loose leather will, naturally, be a dead failure.
After the leather has been forced into its place
the uncut end should be trimmed to make a
good joint. Any unevenness may be trued up
with a file. The new leather will readily ab-
sorb several applications of castor oil before it
becomes smooth and pliable.

Care should be taken that the rivet heads are
countersunk below the surface of the leather.
In case they work flush, owing to the wearing
down of the leather face, they should be riv-
eted. The ** biting" or jerky action of a cone
clutch may often be traced to the rivets work-
ing out, and this will frequently prevent the

244 The Automobile Handbook

clutch from being readily disengaged. Rerivet-
ing will prove an effective remedy in this case,
and considerable additional service may be had
from the leather before it wears down to the
rivet heads.

Combustion Chamber. That part of an ex-
plosive motor in which the gases are com-
pressed, and then fired, usually by an electric
spark, is known as the combustion chamber.
The interior of the combustion chamber should
be as smooth as possible and kept free from
soot, or hard carbon deposits such as are in-
duced by excessive lubrication, or the use of too
rich an explosive mixture.

It will be found to be no small task in design-
ing an explosive motor with the usual form of
valve construction and operation, to keep the
combustion chamber down to the required di-
mensions and at the same time have it free from
bends or contracted passages between the com-
bustion space and the valve chamber.

Many attempts have been made to obviate
this diflficulty by making the combustion cham-
ber simply a straight extension, or continuation
of the cylinder. In this manner both the ad-
mission and exhaust-valves can be placed in the
cylinder itself and an ideal combustion space
secured. This plan has, however, certain dis-
advantages, from the fact that it not only
lengthens the motor, but requires a more com-
plicated form of valve operating mechanism

The Automobile Handbdok

245

than if the valve chamber were at the side of
the cylinder as is usaal.

Commutators^ Ignition. The commutator of

the ignition system of a multi-cylinder gaso-
line motor has a three-fold use : To switch the
battery current in and out of the electrical cir-
cuit at the proper time — To transfer the bat-
tery current successively from one coil to an-
other— To vary the point or time of ignition
of the explosive charge in the motor cylinder.

Fig. 109

The commutator shown in Figure 109 is for
a four-cylinder motor and is designed for use
with induction coils without vibrators, which
are known as single- jump spark coils. The
studs of the screws A and springs B are car-
ried by insulated bushings located in the back
of the commutator case. The nose of the cam
C successively engages with the springs, caus-
ing them in turn to make contact with their
respective screws. The battery and coil circuit
is completed through the screws A, and a

246

The Automobile Handbook

ground to the cam C, by means of the springs
B, when in contact with their respective screws
and the cam.

This device is said to cause a good spark at
the plug on account of the quick break between
the spring and the screw, the electrical circuit
being broken the instant the spring leaves the
screw and before the cam has allowed the
spring to resume its normal position. This form
of commutator cannot be short-circuted by oil

Fig. 110

or dirt getting between the spring and the
screw, as the spring B only forms a part of the*
electrical circuit when in contact with both the
cam C and the screw A.

Another form of commutator for a four-cyl-
inder motor is illustrated in Figure 110, which
has a rotary spring contact-maker A, which
engages successively with the heads B of the
screws C. The screws are spaced equidistant
around the fiber ring D, which also forms the
case of the commutator, and are held in position

The Automobile Handbook

247

by the locknuts E. The spring contact-maker
A is attached to a hub F on the cam shaft of
the motor. The ifime or point of ignition may
be varied by moving the commutator case about
its axis by means of a rod attached to the
arm G.

Figure 111 shows two commutators of very
similar construction. The one at the left in the
drawing is for a two-cylinder motor, and has
flat spring-steel contact-makers. The commu-

Fig. Ill

tator shown at the right of the drawing is for
a four-cylinder motor and instead of having flat
spring contact-makers, it has either carbon or
copper contact-brushes, which are held against
the commutator by short coil springs in the in-
sulated bushings located around the periphery
of the commutator case. The commutator is
made of vulcanized fiber with a short brass or
or copper segment, which is grounded to the
cam shaft as shown.

248 The Automobile Handbook

The forms of commutators illustrated in the
drawings may be constructed for use with a
motor of any number of cylinders, by increas-
ing or decreasing the number of contact-mak-
ers located around the commutator.

Compression. Normal compression in any
given design of motor would be the compres-
sion (cold) fixed by the designer by the rela-
tion of the sweep of the piston to the clearance
space. Normal compression is not the same, as
measured in pounds per square inch, in all mo-
tors. The normal compression as against loss
of compression would be evident to a motorist
in the act of cranking. Were the compression
to become abnormal, as a result of carbon de-
posit, it would be rendered manifest by knock-
ing on a gradient, or by way of pre-ignition.

Limits op Compression. With gasoline vapor
and air, the compression cannot be raised much
above 85 pounds per square inch, but with
the heavier fuels, such as kerosene, a com-
pression as high as 250 pounds per square inch
has been used economically. It has been the
advantages of high compression that has turned
the designer of automobiles toward the heavier
fuels; but, with the increase of compression,
there are many troubles in regard to loss of
power and increased fuel consumption, owing
to the wear of the valves, pistons and cylinders,
which produces a loss in compression and ex-
plosive pressure, and a waste of fuel by leakage.

Compression, How to Calculate. The com-

The Automobile Hcmdbook 249

pression in atmospheres of a motor may be read-
ily found by dividing the cubic contents of the
piston displacement by the cubic contents of
the combustion chamber in cubic inches, and
then adding one to the result.

To ascertain the compression in atmospheres
of a motor, when the cubic contents of the com-
bustion chamber are known: Let S be the
stroke of the piston in inches and A the area of
the cylinder in square inches. If C be the con-
tents of the combustion chamber in cubic inches
and N the required compression in atmospheres,
then

SXA

N=: -fl

Example: Find the compression in atmos-
pheres of a motor of 4-inch bore and 6-inch
stroke, whose combustion chamber has a capac-
ity of 18 cubic inches.

Answer: Six multiplied by 12.56 equals
75.36, which divided by 18 gives 4.19, and 4.19
plus 1 equals 5.19, or the compression in at-
mospheres required. One atmosphere = 14.75.

If it is desired to ascertain the compression
in atmospheres of a motor, the combustion
chamber of which is of such shape that its di-
mensions cannot be accurately calculated, its
cubic contents may be found by filling the com-
bustion chamber with water, and after remov-
ing the water, ascertaining its weight in ounces.

250 The Automobile Handbook

and then multiplying the result by 1.72. This
gives the capacity of the combustion chamber
/ in cubic inches. The compression of the motor
can then be readily calculated from the for-
mula given herewith.

Compression, How to Test for Leaks in. To
discover if there are any leaks in the compres-
sion of a gasoline motor, a small pressure gauge
reading up to 75 pounds should be fitted into
the spark plug opening in the combustion
chamber by means of a reducing bushings When
turning the starting crank of the motor slowly
the gauge should indicate at least 60 pounds
per square inch if the compression is in good
condition.

To test for leaks, fill a small oil can with
soapy water and squirt round every joint where
there may be a possible chance for leakage. Get
an assistant to turn the crank and watch for
bubbles at the joints.

If the joints are all tight, next examine the
condition of the admission and exhaust-valves
and if either of them needs regrinding, it
should be done, first with fine emery powder
and oil, then finished with tripoli and water.

When the valves have been ground to a per-
fect fit, if the compression still leaks, the pis-
ton rings should be examined, as the trouble
will be found to be with them.

Condenser, Use of. A condenser is used in
connection with a Rumkorff, or jump-spark
form of induction coil to take up or absorb the

The Automobile Handbook

251

tic charge of electricity, occasioned by the
f-induction, or electrical reaction in the pri-
ry winding of the coil upon the breaking of
! battery circuit by the interrupter or vibra-
'. This static charge is given tip or dis-

,rged into the primary winding of the coil
ng with the battery current upon the closing
the circi.;t, thus intensifying the action of
secondary winding of the coil in a great de-

ty absorbing the static charge of electricity

252 The Automobile Handbook

the condenser helps to decrease the spark or arc
between the platinum contact points of the in-
terrupter or vibrator, thereby lengthening the
life of the platinum contacts by reducing the
erosive action of the induced current spark. A
jump-spark coil very often refuses to work
properly on account of the condenser connec-
tions having become loose.

The capacity of a condenser is directly pro-
portional to the area of the tinfoil sheets com-
posing it, to the distance between the sheets,
and to the inductive capacity of the dielectric,
or separating medium.

In condenser work it is the custom to cut the
tin-foil sheets to some convenient rectangular
shape, as shown'in Fig. 112, each one with a
neck so that all the + sheets can be soldered to-
gether, on one side, and all the — sheets on the
other. The dielectric paper is cut without
necks, so that the necks of the tin-foil sheets
can be readily contacted with each other, in
such a way, however, that the -|- sheets will
not contact with the — sheets at any point.
The paper is 1 inch wider than the tin-foil, so
that the paper extends out for % inch all
around, and beyond the tin-foil. In the illus-
tration the top sheet of paper is removed to
show the shape of the tin-foil sheets, and it will
be observed that all the tin-foil sheets are of
the same size, but they are so turned that the -|-
sheets have their necks all to one side, while
the — sheets have all their necks to the other

The AvJtomobile Hcmdbook 253

side. Any number of sheets can be used, with
the understanding that a sheet of oil-paper will
be placed between adjacent tin-foil sheets, so
that the -|- and — sheets will not contact with
each other at any point.

If the paper is pierced, or if the + aiid — tin-
foil sheets contact with each other, the con-
denser will fail to perform its functions, and it
sometimes happens that the sheets are punc-
tured in service, thus rendering the condenser
valueless for the intended purpose until the
puncture is repaired, to do which requires that
the fault be found, and a new sheet of paper
substituted.

Condensers are made to fit into housings that
allow of ready application on the instrument
with which they are used. In many cases it is
desirable to use a cylindrical form, while in
others a rectangular outline may be permissible.
Condensers of unusual form are often made from
two long strips of tin foil, laid one upon the
other, and separated by waxed paper or other
insulating material. The long strip is then
rolled or folded into the shape that is desired
and the ends of the foil are attached to the con-
denser terminals.

A punctured or faulty condenser will cause
the spark to be very weak and will also cause
quite violent arcing at the breaker contacts, this
arcing burning and pitting the contacts until
they can no longer carry the current. The con-
denser connections must always be secure.

254 The Automobile Handbook

Cooling Systems. The cooling of a gasoline,
or other automobile engine may seem a simple
thing to the uninitiated, but in reality it is far
from that and it is a fact that the deeper one
goes into it, the more complex the situation be-
comes.

The cooling of internal combustion engines,
in which category automobile engines come, is
divided into two classes, viz., air cooled and
liquid cooled. There are two reasons for cool-
ing the cylinder walls. One is to permit of
proper lubrication, and the other is to prevent
pre-ignition. But it is advisable to allow the
cylinder to work at as high a temperature as
the lubricating oil will stand without carboniz-
ing. The nearer the cylinder temperature can
be kept to 350 degrees the more efficient will
the motor be, speaking from the thermal stand-
point, while on the other hand, mechanical effi-
ciency may be sacrificed by too high tempera-
tures. Therefore, a balance between the two
should be established, and this course is usually
pursued in practice.

AIR-COOLED AUTOMOBIT.E ENGINES. The SUC-

cessful air cooling of an engine cylinder de-
pends chiefly on an abundant flow of cool air
over it. Some cylinders, however, are arranged
1o utilize a more rapid flow than others. Qen-
( Tally spoakiiip:, the designer can take his choice
between a comparatively plain cylinder surface
over which a current of air can flow almost nn-
(!hecked, and a cylinder with its heat-radiating

The Automobile Handbook 2W

surface greatly multiplied by numerous pins,
deep ribs, or other projections. These projec-
tions increase greatly the radiating surface, but
tend to obstruct the flow of air, although they
aid in carrying away the heat. In the latter
case, the velocity of the air stream does not
need to be high, provided it is continuous : while
in the former case, a constant and abundant
supply of air is essential.

AiR-CooLiNG Systems. In modern automobile
practice two systems of cooling are used — ^the
air system and the water system, each of which
has its adherents. As its name indicates, the
air cooling system allows the air to strike the
exterior of the engine cylinder, and thus carry
off the excess of heat generated within it. To
give the radiating surface, required for air
cooling, the exteriors of the cylinders are either
grooved or corrugated, or the surface of the cyl-
inder is studded with metal pins or fins, so as to
present as much surface to the outside air as
possible. The object in the construction of all
air-cooled motors is to make their external sur-
faces offer as great a surface to the air as pos-
sible, and to furnish these surfaces with as large
a supply as possible. A fan is therefore used,
driven by the engine itself, which constantly
directs a current of fresh, unheated air upon
the surface of the cylinder.

Fig. 113 is a sectional view of a vertical air-
cooled gasoline motor. The radiating ribs cast

260 The Automobile Handbook

AIR-COOLED MOTOR

Fig. 113

The Automobile Handbook 257

around the cylinder and valve chamber are
plainly discernible. This motor has a detacha-
ble atmospherically operated admission-valve,
without packing. The valve and cage may be
removed by simply removing two nuts.

Modern forms of air cooling give excellent
satisfaction regardless of the temperature of the
outside air. Individual air leads for each cylin-
der insure even cooling.

Water Circulation. There are two systems
of water circulation in use for cooling the cylin-
ders of explosive motors: The natural or ther-
mo-siphon system and the forced water circu-
lation.

In natural or thermo-siphon water circula-
tion the fact that cold water is heavier than hot
water is taken advantage of. A head of water
is obtained by placing the tank above the level
of the cylinder water-jacket, and as the water
in the jacket is heated by the combustion, the
cooler water from the tank flows in, forcing the
heated water in the tank to take its place, and
in this manner an automatic circulation of wa-
ter is set up. The pipes must be so arranged
that they offer every facility for the free cir-
culation of the water, the cold water leaving
through a pipe at the bottom of the tank and
entering at the lowest point of the cylinder,
while the hot water leaves the top of the cylin-
der and enters the tank at the side near the
top. The water circulation, though automatic,
is very slow, and for this reason requires a

258

The Automobile Handbook

[

DIAGRAM

WATER
TANK

RADIATOR-

TANK-RADIATOR

Fig. 114

larger body of water to produce as p^ood a cool-
ing effect as a forced circulation.

In forced circulation a rotary pump is used.

The Automobile Handbook 259

the 4irection of the flow being such that the
water passes from the pump to the cylinder,
thence to the radiator, on to the tank, and then
through the pump again, thus completing its
circuit. The water in this way gets the maxi-
mum cooling effect from the radiator, and the
body of water in the tank is kept cool. On ac-
count of the high speed of a gasoline automo-
bile motor, and the comparatively small amount
of power required to circulate the water, ro-
tary pumps are much used. As there are no
valves to get out of order, and high speed is
obtainable, this type of pump is very suitable
for automobile use.

In order that a thermo-syphon system may
operate successfully, it is absolutely essential
that the water passages around the cylinders, as
well as the connections to the radiator, be of
large capacity and perfectly free from obstruc-
tions. Sharp bends should be avoided in every

case.

Overheating — Causes of. Overheating of the
engiiie, when not traced to poor circulation, is
almost always caused by too much gasoline.
There are, however, many possible causes of
over rich mixture, some of which on the
face of them might seem to be causes of lean
mixture rather than rich. Prominent among
these latter is too low a gasoline level in the
float chamber due to the float valve closing too
soon. The immediate effect of this is to make
the mixture too lean at starting, and at low

260 The Automobile Handbook

speeds. Starting is therefore diflScult, and if
the auxiliary air valve begins to open at the
usual motor speed, the mixture will again be
much too lean. These symptoms, however, un-
less properly interpreted will probably lead the
owner to increase the gasoline supply, or to ad-
just the spring tension of the auxiliary valve so
that the latter will not open until quite high
speed is attained. In other words, he adjusts
to give a suitable mixture at one speed, and at
other speeds the mixture is extravagantly over
rich. It is well not to be too easily satisfied
with the carbureter's performance, as it may
be found that one fault such as the above has
been imperfectly offset by another fault in the
other direction instead of the correct adjust-
ment being made where the fault really lies. A
good carbureter will give a sensibly correct
mixture at all speeds within the ordinary range
of the engine. If it fails to do this the thing to
do is to investigate until the trouble is found.

Insufficient lubrication increases the friction
between the piston and cylinder, and so gener-
ates extra heat. Bad or unsuitable oil may
have the same effect.

Wear of the cams, tappets and valve stems
may be the cause of overheating, as it would
not require much loss from the faces of the va-
rious moving parts that come in contact to
cause a more or less appreciable difference in
the operation of the valves, and as this wear
tends to bring about a later action, it may be

The Automobile Handbook 261

sufficient in the case of the exhaust valve to
retain the burnt charge considerably beyond
the time at which it should be allowed to es-
cape. Where a motor runs at a speed of 800
revolutions per minute or over, it will be evi-
dent that it is a matter of very small fractions
of a second.

Another cause of overheating may be the de-
posit of a fine film of scale on the inside of the
circulating pipes and radiator. This scale is of
a mineral nature, and, in addition to being an
excellent nonconductor of heat, it is deposited
in such intimate contact with the metal that the
latter is practically insulated and its radiating
power entirely lost.

Overheating — Effects of. The immediate
effect of overheating is to burn up the oil in the
cylinders, or crank case. This causes a smell
of burning, and an ordor of hot metal. There is
sometimes a slight smoke and the motor will
make a knocking sound. The cooling water be-
gins to steam, and the car will gradually slow
down and finally stop.

The most serious cause of a stoppage on the
road is overheating, which causes the lubricat-
ing oil to burn up and the piston to expand and
grip or seize in the cylinder.

Overheating — Kemedies for. As soon as any
of the above symptoms are noticed:

The motor should be stopped at once.

Kerosene should be copiously injected into

262 The Automobile Handbook

the cylinders and the motor turned by hand to
free the piston-rings.

The parts should then be allowed to cool.

Do not pour cold water on the cylinder jack-
ets, for fear of cracking them, but pour the wa-
ter into the tank so as to warm the water before
it reaches the cylinder jackets.

A simple test in the case of an overheated
motor is to let a few drops of water fall on the
head of the cylinder. If it sizzles for a few mo-
ments the overheating is not bad, but if the
water at once turns into steam, the case is seri-
ous.

Detach the spark plug or plugs, and turn the
starting-crank slowly. This draws in cold air
and cools the inside of the cylinder and the pis-
ton.

After the parts are cool, it will be advisable
to put some oil in each cylinder.

Dalton's Laws. The relation between the
vapor tension and the quality of vapor is ex-
pressed by two laws known as Dalton's laws,
as follows:

I. The pressure, and consequently the quan-
tity, of vapor that will saturate a given space
are the same for the same temperature, whether
the space contains a gas, or is a vacuum.

II. The pressure of the mixture of a gas and
a vapor is equal to the sum of the pressures that
each Avould exert if it occupied the same space
alone.

If a volatile liquid is added to a gas, and the

The Automdhif,e Handbook 263

resulting mixture of gas and vapor is allowed
to expand so that the pressure remains un-
changed, the volume of the mixture will exceed
the original volume of the gas. The ratio of
this new volume to the original volume of the
gas is equal to the ratio between the combined
pressure of the gas and vapor, and the pressure
of the gas alone, had the volume remained con-
stant.

Deposits in Water Jacket. If the cooling
water contains lime or alkali, the heating of the
water in the jacket will cause these solid sub-
stances to be deposited in the cooling spaces.
This will soon choke any narrow ports and pre-
vent proper circulation, resulting in overheat-
ing, rapid wearing of the valves, and loss of
power and efficiency. A simple remedy consists
of the application, at regular intervals, of a di-
lute solution of hydrochloric, or muriatic, acid,
made as follows: Dilute one part of muriatic
acid with nineteen parts of water, and, after
draining the jacket completely, pour in enough
of the solution to fill the entire cooling space.
Allow the mixture to remain in the jacket for
not more than 8 to 12 hours, after which wash
the cooling space thoroughly by running clear
water through it. If the solution is permitted

to remain in the jacket longer than the period

•

stated, there is danger that the metal may be
damaged by the action of the acid. The acid
will soften and dissolve the lime or alkali, and
the clean water will remove it from the jacket.

264 The Automobile Handbook

It is generally sufficient to apply this method
of removing the deposits once every two weeks.
If neglected too long, the acid will not'dissolve
the deposit.

Differential Gears. So long as an automo-
bile moves in a perfectly straight path, its two
driving wheels turn at equal speed, since they
must cover equal distances in equal periods of
time, and it would be perfectly allowable that
the two wheels should be locked together, as
there would be no relative motion between
them. The power could be transmitted to
either one, or to both of them with perfectly
satisfactory results under these circumstances.
When, however, a car is to be moved in a curved
path, as in turning a corner, the driving wheels
must move at different speeds, since the out-
side one has to cover a longer distance in the
same time than does the wheel which is on the
inside of the curve. If the two wheels were
locked together under these conditions, one or
both of them would be forced to slip, as the
speeds transmitted to them would be equal,
while the distances they are to travel are un-
equal. This difficulty is successfully overcome
by the use of the differential gear which trans-
mits the power from the change-speed gear to
the rear axle, or driving Avheels of the car.
Differential gears consist of a set of four or
more gears attached to the ends of two shafts
that meet, and are usually in line, so that
both are rotated in the same direction. But, if

The Automobile Handbook

265

either meets with extra resistance it may rotate
more slowly than the other, or may stop alto-
gether. .

These gears are used on the driving axles
of automobiles. The axle is made in two parts,
with a gear on the end of each, where the parts
come together. Other gears mesh with both
these axle gears, and are driven from the engine
by a sprocket and chain, or by bevel gears and
shaft. These gears turn the axle, but permit

Fig. 115
Bevel Gear Differential With Bevel Driving Gear

and Pinion

its two parts to turn in respect to each other

so as to allow the automobile to go around a

corner without causing the wheels to slide, or

skid. The rear wheels are each fixed to a half

of the rear axle, and both receive power,

hence it is necessary to allow one wheel to turn

at a different speed from the other, and this

is accomplished vy means of the differential

gear.

266 The Automobile Handbook

Bevel Gear Differential. Fig. 117 shows a
bevel gear differential in which A and B are the
two halves of the rear axle, which is divided at
its center. One of the driving wheels is carried
on A, and the other one on B, while the inner
ends of the two half axles are each fitted with
bevel gear wheels C and D. Meshing with
these two bevel gears are two, three or four
bevel gears, two of which are shown at E and
F. These pinions are supported on radial studs
which project inwardly from the casing. Upon
this casing are sprocket or bevel gear teeth
which are driven from the engine. The teeth of
each pinion, E and F are at all times in mesh
with the teeth of both the bevel gears C and D
on the axle. When the car is in operation, the
chain or bevel drive revolves the case contain-
ing the pinions, and the power is transmitted
through the teeth of the pinions E and F to the
teeth of the gears C and D and thence to the
axle and wheels. So long as the vehicle travels
in a straight line, the pinions act as stationary
driving members, and have no occasion to re-
volve, as the two halves of the axle and their
gears are moving at equal speeds. They merely
revolve with the frame. The same teeth of the
bevel pinions and gears are in contact so long
as a straight path is traversed. When, however,
the car is steered in a curve and different veloc-
ities are required in the drivers and the bevel
gears with which they are connected, the pin-

The AutOTtiobile Handbook

267

ions no longer act as fixed driving members,
but each turns upon its stud and allows the
necessary relative motion between the two bevel
gears, and at the same time they continually
transmit power to the two ends of the axle be-
cause they are always in mesh with each other.
This compensating action may continue indefi-
nitely through any amount of variation be-
tween the driving wheel rotation, because one

tooth of the pinions comes into play as fast as
the preceding one disengages with the bevel
wheels on the shaft. Fig. 116 presents a larger
view of the bevel gear differential, the two
gears on the rear axle being shown as secured
to the shaft, and to a sleeve on the shaft. The
differential employed here has three bevel pin-
ions turning on radial studs, which are secured
to the arms of a spider at their inner end, A
differential bevel gear, allhough most exten-

268

The Automobile Handbook

sively used, is open to the objection that the
bevel gears impose an end thrust upon the two
halves of the mainshaft on rear axle. This has
led to the design of differentials in which only
spur gears are used.

Fig. 117.
Bevel Gear Differential.

Bevel Gear Differential. Fig. 118 shows
a semi-sectional view of the bevel differential
gear. The engine shaft carries a bevel gear
wheel shown in section at a. This gear meshes
with the large bevel gear b, on the differential
gear case c. On the inside of this gear case
are carried a number of small bevel gears, one
of which is shown in section at d. These are
free to turn on the studs that hold them to the
gear case. These gears in turn mesh with bevel
gears e and f, on the ends of the half axles.

The principle governing the action of the
bevel gear differential is similar to that of the

The Automobile Handbook 269

spur gear differential. When the two bevel
gears e and £ on the half axles meet with the
same resistance, the small bevel gears d do not
turn on their bearings ; but when the movement
of one of the gears e or f is resisted more than

that of the other it lags behind, causing the
small bevel gears d to turn on their axles suffi-
ciently to equalize the resistance.

Spur Gear Diffekential. In the spur dif-
ferential, bevel gears are replaced by gears of

270

The Automobile Handbook

the spur type, as shown in Pig, 119, a large
spur gear being secured to each half axle, as
shown at A and B, exactly as are the bevel
gears. A double set of spur pinions, E and F,
having their bearings in the frame, revolve

upon axes parallel with the axle. For each
hcvi'l pinion is substituted a pair of spur gears,
E and F, whipli mesh with each other, and at
the same time each one of them is in mesh with
one of the large gears. The combination of the

The Automobile Handbook 271

motion of each pinion of the pair upon its gear,
and the motion of the pair upon each other
produces, the same effect as the use of a bevel
pinion. When the vehicle is roundiog a curve,
one rear wheel moves less rapidly, causing tho
pinions with which it is geared to revolve upon
their bearings, and thus compensate for the in-
creased resistance.

Testing Dipperential Gears. The differen-
tial gear should be tested with a view to locat-
ing any wear or side play. This may be done
by jacking up the rear axle and shaking one

272 The Automobile Handbook

wheel forward and backward while the other
is held stationary, and noting how far the
wheel must be turned before the movement is
taken up by the flywheel of the engine. Any
noticeable play will generally be found either
in the center pinions of studs of the differential
gear, in the large and small bevel gears, in the
clutch sleeve, or in the universal joints. The
differential gear^ and live axle of modern ears
seldom give trouble if kept properly lubricated,
and the car's mileage should run up into many
thousands before any considerable amount of
play is evident. The joint pins of the propeller
shaft may become loose through wear, in which
case a knocking noise in the transmission gear
will indicate the cause and location of the
trouble. These pins may be readily replaced
with new ones at small cost. If the play is
found in the bevel gears, the small gear should
be adjusted to mesh deeper with its larger mate.
This may be done by means of the adjustable
locking ring or by inserting a washer of the
jn-oper thickness. It may be found, however,
that no adjustment is necessary, and a thor-
o\\^\\ cleaning with gasoline to remove all oil
and grease will be all that is required. The
ease should then be refilled with the quantity
of oil and grease recommended by the manu-
facturers.

Distributers. Instead of employing a sepa-
rat«^ spark coil for each cylinder of a multi-
cylinder engine, the primary circuits of which

The Automobile Handbook 273

are made and interrupted in rotation, a device
known as the distributer may be used, which
permits of any number of cylinders being
sparked from a single coil. In magnetos de-
signed for jump spark ignition of multi-cylin-
der engines the distributer forms part of the
magneto and is rotated by it. The distributer
is nothing more than a timer of secondary cur-
rent, and generally consists of a cylindrical shell
of insulating material, upon the inside of the
cylindrical surface of which equidistant metal-
lic segments in number equal to the motor cyl-
inders are inserted. A conducting arm rotat-
ing upon a shaft concentric with the insulated
shell carries a brush, which successively makes
contact with the segments. The arm is in per-
manent electrical connection with the free sec-
ondary terminal of the coil, and each one of
the segments is wired to the spark plug of a
cylinder.

In the case of four-cylinder motors the
moving arm is geared at one-half the speed of
the motor, thus making contact for each cyl-
inder once in each two revolutions or complete

274 The Automobile Handbook

Dynamometer. A dynamometer is a form of
equalizing gear which is attached between a
source of power and a piece of machinery when
it is desired to ascertain the power necessary to
operate the machinery with a given rate of speed.

Electricity, Forms of. Electricity or electri-
cal energy may be generated in several ways —
mechanically, chemically and statically or by
friction. By whatever means it is produced,
there are many properties which are common
to all. There are also distinctive properties.
The current supplied by the stor^e battery
will flow continuously until the battery is prac-
ticq,lly exhausted, while the current from a dry
battery can only be used intermittently ; that is,
it must have slight periods of rest, no matter
how short they may be.

The dynamo or magneto current is primarily
of an alternating nature, or one which reverses
its direction of flow rapidly. In use, this alter-
nating current is changed into a direct or con-
tinuous current flowing in one direction only,
by means of a commutator. Any of the forms
described are capable of igniting an explosive
charge in a motor cylinder, but the static or
frictional form of electricity is not used for this
purpose on account of its erratic nature.

Electric Apparatus. — Care of. The following
instructions apply particularly to electric ap-
paratus in connection with the operation of au-
tomobiles. Look over the electrical plant and
replace worn wires with new. Clean out the

The Automobile Handbook 275

timer with gasoline and lubricate with light oil.
The magneto need not be taken apart, as it will
probably only need a little surface cleaning, a
few drops of oil, and the amateur had better
not meddle with its internal mechanism. The
storage battery should be examined, and if the
brown deposit collects in any quantity at the
bottom, the electrolyte should be poured out
into a glass bottle, and the battery washed out
with clear water (rain water preferred). Clean
the top of the battery and make it a point to
keep it clean and free from acid. Clean the
terminals of any corrosion, and see that the air
vents are not clogged up. If the accumulator
has been neglected, either in the electrolyte
having been allowed to get below the proper
level or in not giving it the regular monthly
** charge,'' it may get a bad case of sulphating.
To get the battery into its normal condition,
empty out the electrolyte and wash the case
thoroughly with soft water. Pour in only
about seven-eighths of the acid solution and fill
up with distilled water to cover the top of the
plates. The battery should then be charged
with a low current until the plates are restored
to their normal condition. If very badly sul-
phated, the white coating should be washed off
with a rag, and in case this fails to remove it,
scraping must be resorted to. If the electro-
lyte is not sufficient to cover the top of the
plates, fill up with distilled water so that the
liquid will just cover them. The specific grav-

276 The Automobile Handbook

ity of the electrolyte should not be less than
1.150, and, although varying somewhat, a hy-
drometer reading of 1.250 is recommended.
This is approximately 1 part of sulphuric acid
to 4^2 parts of water, which will be found suf-
ficiently accurate if no hydrometer is at hand.
If the electrolyte should test lower than the
first figure, add pure sulphuric acid until the
1.250 mark is reached.

In case the plates are broken down or
** buckled," or if the paste has dropped out of
the pockets of the grids, the accumulator should
be sent to the manufacturers for repair. In
some accumulators the liquid is not used, but a
jelly made of silicate of sodium and dilute
sulphuric acid takes its place. If your battery
is of this type, it is well to remember that the
jelly must be kept moist on the top, and as the
emulsion becomes dry a little water should be
added to replace that which is lost through
evaporation.

The contact points of the coil will probably
require adjusting. This is very easily accom-
plished by trimming up the points with emery
paper. Do not rub away the metal unneces-
sarily, only removing enough to true the points
so that they make a good contact. In adjust-
ing the vibrator, remember that a light tension
is much better than a stiff tension. A light
flexible vibration with a moderately high-
pitched buzzing note will not only give a better
spark, but will keep the points in better shape.

The Automobile Handbook 277

A heavy tension will make the coil less respon-
sive and will pit the contact points and exhaust
the battery more quickly. As a coil will ren-
der the most efficient service only when the vi-
brators are adjusted as nearly alike as possible,
a special ammeter is often used to determine
the current consumption of each unit. The am-
meter should show a reading of 6-10 amperes.

Electric Horsepower. See Horsepower.

Electric Ignition. See Ignition.

Electric Lighting and Starting. See Start-
ing and Lighting Systems.

Electric Lighting and Starting. See last part
of this volume.

Electromotive Force, Definition of. The
cause of a manifestation of energy is force; if
it be electric energy in current form it is called
electromotive force. An electromotive force
or pressure of one volt will force one ampere
through one ohm of resistance.

278 The Automobile Handbook

Engines, Internal Combustion.

Engine — Construction of. An automobile
engine should answer the' following require-
ments in order to meet the demands of the mo-
tor user: It must be of light weight in propor-
tion to its horse power, so that as large a pro-
portion of its power as possible may be avail-
able for propelling the useful load, and but lit-
tle demanded to move its own weight; it must
be compact, in order that it shall not occupy
too large a proportion of the available room of
the car ; it must operate without undue noise
and vibration; it must be fully enclosed as a
protection against the weather, and still it must
be so located as to be easily accessible for in-
spection, oiling and repairs; its operation must
be automatic for considerable periods of time,
as regards cooling and lubrication; it must be
capable of running very slowly, or very fast at
will, and of developing little, or much power ; it
must be supported upon the car in such a man-
ner that its power may be most readily and
efficiently transmitted to the driving wheels,
and it must further be carried upon springs so
that the jar and shock from the road shall not
be transmitted to it.

Explosive Motors. Explosive motors are of
three forms, known as stationary, marine and
automobile. Their general characteristics are

The Automobile Handbook 279

implied by their various designations. The sta-
tionary motor may be either vertical or hori-
zontal. Marine motors, designed for applica-
tion to boats, are almost invariably vertical.
Automobile motors are of comparatively recent
introduction and of great variety, the aim of
the designers being to secure the maximum of
power and minimum of weight. They also
may be vertical or horizontal.

These three forms may be again divided into
two-cycle and four-cycle types. In the former
an explosion occurs at every revolution. In the
latter there is an explosion at every alternate
revolution.

Explosive motors are dependent for success-
ful operation on two things: First, a charge of
gas or vapor, mixed with sufficient air to pro-
duce an explosive mixture, and second, a
method of firing the charge after it has been
taken into the combustion chamber of the
motor.

When coal gas is used the supply is taken
from the main and mixed directly with the nec-
essary proportion of air. When gasoline is
used, air is mixed with it in the correct pro-
portion by carbureting devices.

After the charge of gas and air has been
taken into the cylinder it is compressed, as will
be shown later, by the action of the motor itself
and then fired, usually by an electric spark
actuated by the motor, but sometimes by the
use of a tube screwed into the cylinder and

280 The Avtomoiile Handbook

The Auioinobile Handbook 281

Internal Combustion Automobile Engine. 1, Oil
Valve Lever. 2, Oil Valve Adjustment. 3, Oil
Valve Lifter. 4, Oil Valve Slot. 5, Oil Tank
Cover. 6, Water Jacket. 7, Oil Tank. 8, Oil
Valve Spring. 9, Oil Valve Plunger. 10, Oil. 11,
Oil Gauge Glass. 12, Oil Valve. 13, Oil Feed
Window. 14, Water Inlet. 15, Cylinder Joint.
16, Cylinder Wall. 17, Crank Case Breather.
18, Oil Feed Pipe. 19, Connecting Rod Bear-
ing. 20, Crank Pin. 21, Rod Bearing Bolt.
22, Oil Scoop. 23, Crank Shaft Timing Gear.
24, Crank Case. 25, Oil Lever Overflow. 26,
Crankcase Oil. 27, Oil Drain Cock. 28, Cam
Shaft Timing Gear. 29, Cam Shaft Plate. 30,
Cam Shaft. 31, Cam Shaft Housing. 32, Ex-
haust Outlet. 33, Gasoline Pipe to Carburetor.
34, Carburetor Priming Lever. 35, Carburetor.
36, Throttle Lever Rod. 37, Gasoline Adjust-
ment. 38, Valve Lifter Rod. 39, Valve Stem
Adjustment. 40, Fibre in Valve Plunger. 41,
Cylinder Space. 42, Valve Spring. 43, Ex-
haust Pipe. 44, Connecting Rod. 45, Piston.
46, Wrist Pin Set Screw. 47, Oil Groove in
Piston. 48, Wrist Pin. 49, Exhaust Manifold.
50, Manifold Clamp Nut. 51, Intake Manifold.
52, Intake Passage in Cylinder. 53, Valve Stem.
54, Valve Head. 55, Valve Opening, Seat and
Face. 56, Piston Rings. 57, Combustion Space.
58, Valve Pocket. 59, Priming Cup. 60, Valve
Cap. 61, Water Outlet Header. 63, Valve Cap.

282 The Automobile Handbook

The Automobile Handbook 283

heated from the outside, the heat, of course,
being communicated to the gas. The resulting
explosion operates the motor.

The principal parts of a four-cycle explosive
motor are the cylinder, the piston, the piston
rings which fit into grooves in the piston : two
sets of valves, one to admit the charge and the
other to permit it to escape after the explosion ;
a crank shaft and connecting rod which con-
nect it with the piston head, and a flywheel,
whose presence insures steady running of the
motor, and whose further functions will be
better understood as the description proceeds.
In the two-cycle form of motor there is really
but one valve, the exhaust and admission-ports
being covered and uncovered by the piston it-
self.

All of the parts referred to are of the motor
proper. Other parts, which are separate from
the motor but on which its operation depends,
are the carbureter, which supplies the charge
of gasoline vapor and air for a gasoline motor,
or a mixing chamber for mixing air and gas in
the case of a gas motor, and the batteries and
other parts of the electrical ignition device.

A part w^hich has no connection with the
actual running of the motor but with which
practically all are fitted is the muffler, whose
purpose is to deaden the sound of the explo-
sion.

The cylinders of all except very small motors
are as a rule partly encased in a chamber

284 The Automobile Handbook

through which water is circulated, the object
of this heing to keep the cylinder cooL

Pig. 123
Section Through Six Cylinder Long Stroke Engine

Offset CRANKsnAFTS. The practice of off-
setting the crankshaft in automobile motors is
rapidly gaining converts, and there are namer>-
ous examples of offsetting to be seen at the

The Automobile Handbook 285

present time. In this scheme, it will be remem-
bered, the crankshaft is not set in the plane of
the middle of the cylinders. In other words,
the crankshaft is set slightly to one side. The
exact amount of this oifset seems to be variable

with different designers, but the object is al-
ways the same. When the piston is in the po-
sition of maximum compression involving the
ignition and flame propagation, it is the idea
to have the connecting rod in the vertical po-

286

The Automobile Hcmdbook

sition. The force of the explosion will then
come on the connecting rod endwise and the
piston will not be pressed unduly against the
cylinder walls.

Offset Crank Shaft Engine — Timing the
Valves. To time the valves of an engine hav-
ing an offset crankshaft, the inclination of the
axis of the connecting rod must be taken into
account. As Figure 124 shows, the connecting
rod is vertical, and if the shaft center were not

Fig. 125
Diagrams Showing the Four Positions of the Offset

Crankshaft

to one side, the flywheel would be marked at
the exact center of the upper face, namely, at C.
In the case where the center is set over, the rod,
when in a vertical position as at G is not at
the end of the stroke. If the flywheel were
marked at C it would not indicate correctly the
lower dead center. This does not appear until
the three centers, piston pin, crank pin, and
crankshaft are in line, as shown by the line
D E F. The flywheel should be marked at this

The Automobile Handbook 287

point, and the mark may be on a vQltieal line
through the crankshaft center or on a diagonal
as \ the line just indicated. In the latter in-
stance, the mark for the lower center would be
at H.

Similarly, the upper dead center, if marked,
would be at a vertical point above the shaft
center as C, but would assume a different posi-
tion, located on a diagonal, as at A, on the cen-
ter line ABB.

Of course, in actual timing, the upper and
lower centers are not used, as good practice de-
crees an overlap for the valve action, but they
have been used as an illustration in this case be-
cause their use simplifies the matter.

In Fig. 125, the actual marking of a fly-
wheel is shown for a complete cycle. In this the
angles selected follow the best modern prac-
tice, being as follows : Inlet opens at 8 degrees
past the upper center, and closes at 26 past the
lower center, giving an inlet opening, total, of
198 degrees. Exhaust opens at 46 degrees be-
:fore the lower center and closes at 5 past the
Tipper. This gives the whole angle for the ex-
laust, 231 degrees on the crankshaft.

As shown, the markings are put on the fly-
-wheel directly above the center of the crank -
ishaft, but the offset is taken into account.

Pistons. '-The piston used in a gasoline motor
csylinder is of the single-acting or trunk type.
it is made of an iron casting which is a good
^Vsrorking fit in the cylindigr. Around the upper

288 The Automobile Handbook

end of the piston three or four grooves are <
and in these grooves the piston-rings fit. '
rings are made of east iron, and the bore of
ring being eccentric to its outer diameter, tl
is a certain amount of spring in them, and
pressure is caused against the cylinder ^
preventing any of the expanding gases pass
the piston.

Piston Materials. Until recently it has \
the universal practice to make internal coml
tion engine pistons of cast iron for the rea
that this material does not warp under hea
such an extent as does steel. The princi
objection to cast iron has been its comparatii
high weight, this weight being necessary bec«
of the lack of great strength in the metal. 1
a well known fact that cast iron is very brii
With the advent of the modern high speed
gine, experiments were conducted with steel
tons because of the fact that they allowed
lighter construction with equal strength. S
pistons have done satisfactory work, but are "%
high in production cost, and this has prever
their general introduction.

The necessity for reducing the weight of
reciprocating parts has more recently led to
introduction and use of pistons made from all
of aluminum, which, of course, giveg the desi
reduction in weight. The fit of the piston in
cylinder cannot be so tight when cold as "V
cast iron or steel, but as soon as the engine
run a few moments, the expansion due to 1

The Automobile Handbook - 289

allows the piston to fit close enough for all prac-
tical purposes. These pistons are now fitted in
many makes and models of stock cars and may
be fitted to cars already in use.

Piston Displacement. The piston displace-
ment of a motor is the volume swept out by the
piston, and is equal to tne area of the cylinder
multiplied by the stroke of the piston. The
expression, cylinder volume, is sometimes con-
founded with the term piston displacement.
This is erroneous, as the cylinder volume is
equal to the piston displacement, plus the com-
bustion space in the cylinder head.

Pistons, Length op. For vertical cylinder
motors the length of the piston should not on
any account be less than its diameter, while a
length equal to one and one-quarter or even
one and one-third diameters is better. For mo-
tors with horizontal cylinders the length of the
piston, in any case, should not be less than one
and one-third diameters, and if possible one
and one-half diameters or over.

Piston Position. There is nothing more con-
fusing to many motorists — not only to the be-
ginner, but to many who are proficient in the
general care and operation of their motor cars
— than the relative various positions, in a four-
cycle engine, of the four pistons on any of their
four cycles of compression, work, explosion,
and exhaust, this being the order of the cycles.

In the following illustrations the pistons are
shown as they are usually placed in relation to

390 The Aittomobile Handbook

The Automobile Handbook 291

■

■'^

" 1

[

292 The Automobile Handbook

one another. That is, pistons 1 and 4 are at
the top of their strokes when pistons 2 and 3
are at the bottom, and, obviously, vice versa.
The figures over the pistons in each diagram
represent their order of number, counting from
either end of the engine.

In Fig. 126, cylinder I is ready to descend
on its intake stroke — ^having tinished its ex-
haust stroke— and cylinder 4 is ready to de-
scend on its working stroke — ^having finished
its compression stroke. Cylinders 2 and 3 are
ready to move on their up strokes. No. 2 on its
compression, having finished its intake, and
No. 3 on its exhaust, having finished its working
stroke. The results are that the pistons are
brought into the positions shown in Fig. 127.
This means that cylinder No. 1, having com-
pleted its intake downward stroke, is ready for
its compression up stroke ; No. 2 has moved up
on compression and is ready to go down on
work; No. 3 has finished exhausting and is
ready for intake and No. 4 has finished the.
work stroke and is ready to move up on ex-
haust. Piston No. 2, having completed its work
stroke, the pistons are brought back to the po-
sitions shown in Fig. 126, but with an altered
condition of the cycle represented by each, as
shown in Ficr. 128. The pistons are now ready
to move to the positions shown in diagram 2,
with an altered cycle condition. Cylinder No.
1 moves down on work; No. 2 up on exhaust;

The Automohile Hcmdhook 293

No. 3 up on compression and No. 4 down on in-
take, see Fig. 129.

When the cycle of each has heen completed,
from the above starting points of No. 1, ex-
haust; No. 2, intake; No. 3, work, and No. 4,
compression, the pistons are then back not only
in the position of Fig. 126, but with the same
condition of cycles.

This explanation has been in the order of the
cylinder numbers, but the effect of each cycle
of each cylinder will be easier traced if it be
remembered that the order in which the cylin-
ders work is : Cylinder 1, then cylinder 3, then
cylinder 4, and then cylinder 2, and then repeat
indefinitely. From this and the above illustra-
tions it will be easily understood that as piston
No. 1 goes down on its work stroke, No. 3
comes up on compression stroke, and is then
ready for the work, which is a down stroke
bringing No. 4 up on compression. No. 4 then
goes down on work and brings No. 2 up on com-
pression, then it goes down on work and brings
No. 1 up on compression for the repeating of
cycles. This shows that each synchronized pair,
1-4 and 2-3, always have one cycle between them
as they move together, either up or down.

Piston-Rings. To ensure proper compression,
it is absolutely essential that the piston-rings
should be kept lubricated; consequently when
the motor has been idle for some time, the
compression at the start is often poor. Any fail-
ure in the lubrication while running will, of

294 The Automobile Handbook

course, have the same effect, such, for example,
as in the case of overheating, or when the sup-
ply is intermittent. Sometimes the piston-
rings get stuck in their grooves with burnt oil,
through overheating, and the compression es-
capes past them. Thorough cleaning with kero-
sene, and fresh lubricating oil will settle the
matter. In motors where the rings are not
pinned in position, the slots may work round so
as to coincide. In this case they will have to be
moved around. Sometimes burnt oil may, ap-
parently, have the opposite effect on piston-
rings, for by causing the piston to grip in the
cylinder, it will produce considerable resist-
ance, and the operator might erroneously think
in consequence that his compression is good. In
every case, after a long run, a little kerosene
should be injected into the cylinders to clean
the rings.

Piston-Rings — Method of Turning. A pat-
tern should be made from which to cast a blank
cylinder or sleeve with two projecting slotted
lugs on one end to bolt same to face plate of
lathe. This blank should first be turned off out-
side to the required diameter, makinic: it, of
course, sufficiently lar^ror to allow for the cut
in the rin^rs, after cutting from the blank. The
blank should then be set over eccentric suffi-
ciently to allow the thick side of the rings to be
twice the thicknc^ss of the thin side after turn-
ing. The inside of th(» blank can then be bored
out, and the rings cut off to the exact thick-

The Automobile Handbook

295

ness required with a good sharp cutting off tool.
A mandrel or arbor should be made with two
east iron washers or collars to fit it, one fas-
tened to the mandrel and the other loose, with
lock nut on mandrel with which to tighten up
the loose collar. After the rings have been
sawed open and a piece cut out the required
length, they can be placed on a collar or ring

nssn

^ssNs^^v^^\v^^^:^^^\^^

FOUR-CYCLE MOTOR DIAGRAM

Fig. 130.

about 1-32 to 3-64 of an inch larger than the
cylinder bore, and slipped on to the mandrel one
at a time, of course, with the loose collar and
nut off the same. The loose collar and nut can
then be put on the mandrel, the ring clamped
tightly between the two collars, the mandrel
put in the lathe and the ring turned off, without
leaving any fins or having to cut the ring off
afterward as is done in many cases. This is the
only way in which a perfectly true ring can be

296 The Aiitomohile Handbook

Four-Cycle Motor. Fig. 130 furnishes two
sectional views of a four-cycle type of motor
with some of the parts removed, as in Fig. 121.
It shows a cylinder C, admission-valve A, a
piston P, and exhaust-valve E.

The left-hand view shows the piston P about
to suck in a charge of vapor, by the same
method as previously described, through the
admission-valve A into the cylinder C. The suc-
tion continues until the piston P reaches the
position shown in the right-hand view. Then
the piston returns until it again arrives at the
position shown in the left-hand view, compress-
ing the charge of mixture during this operation.
Just before the piston arrives at the end of its
travel in this direction, the charge of vapor,
now under compression, is ignited by the
method previously explained and its expansion
forces the piston back to the position shown in
the right-hand view. When the piston has, for
the second time, reached the position shown in
the right-hand drawing, a mechanical device
opens the exhaust-valve. The exhaust-valve
remains open until the piston has again arrived
at the position in the left-hand view. Then it
closes, the piston again commences to draw in
a cliarge of vapor and the cycle of operation
of the motor is repeated.

FoT'R-CvcLE Motor, Operation op. A four-
cycle motor has only one working stroke or im-
pulse for each two revolutions. During these

The Automobile Handbook

297

two revolutions which complete the cycle of
the motor, six operations are performed :

1. Admission of an explosive charge of gas,
or gasoline vapor and air to the motor-cylinder,

2.. Compression of the explosive charge.

3. Ignition of the compTessed charge by a
hot tube, or an electric spark.

Fig. 131
Four -Cylinder Engine

4. Explosion or extremely sudden rise in the
pressure of the compressed charge, from the in-
crease in temperature after ignition.

5. Expansion of the burning cliarge during
the working stroke of the motor-piston,

6. Exhaust or expulsion of the burned gases
from the motor- cylinder.

298

The Automobile Handbook

Two-Cycle Motor. The foregoing outline of
the functions of the parts of the motor prepares
us for a description of the two-cycle form of
motor. This particular form of motor draws
in a charge of gas or vapor, compresses it, fires
it and discharges the product of combustion or
burned gases while the crank makes but a sin-

TZOk

TWO-CYCLE MOTOR DIAGRAM

Fig. 132

gle revolution, and while the piston makes one
complete travel backward and forward.

Fig. 132 shows two sectional views — ^that is
to say, views of the motor cut in two, longi-
tudinally— of the principal parts of a two-cycle
motor. Other parts, such as the crankshaft.
connecting rod and flywheel, are omitted to
avoid confusion. C is the crankcase and A
the admission valve, through which the vapor

The Automobile Handbook 299

passes to the ^ crank ease. B is the inlet pas-
sage, through which it passes from the crank
chamber to the cylinder. P is the piston. The
igniter, which makes the electric spark when
the lower point comes in contact with the up-
per, is shown immediately below the cylinder
cover. This causes the explosion of the vapor.
E is the exhaust port, through which the burned
charge escapes after the piston has been driven
outward by the explosion and has reached the
end of its stroke.

Let it be supposed that the motor is still and
the crank chamber C is full of gas or vapor.
To start the motor the piston is started by
means of a crank on the flywheel shaft, and as
it passes to the position shown in the left-hand
drawing it forces the charge of vapor through
the port B into the cylinder. The piston then
returns to the position shown in the right-hand
view, moving away from the crank chamber C,
and in doing so closes the port B and the ex-
haust opening E and compresses the charge of
vapor. The points of the igniter come together,
a spark occurs and the resulting explosion
forces the piston outward again. When the pis-
ton reaches a point near the end of the stroke,
as shown in the left-hand drawing, it uncovers
the port E and the burned charge passes out,
the new charge coming through the port B im-
mediately afterwards.

The admission of the new charge to the crank
chamber is controlled by the action of the pis-

300 The Automobile Handbook

ton. As the latter travels outward it has a
tendency to create a vacuum in the crank
chamber. This draws the valve inward and
admits the charge of vapor.

It will be observed that there is a projection
on the head of the piston. This is generally
known as a baffle-plate. Its object is to pre-
vent the incoming charge from passing di-
rectly across the cylinder and out at the ex-
haust port E, which, it will be observed, is di-
rectly opposite it. The baffle-plate directs the
incoming charge toward the combustion cham-
])er end of the cylinder, providing as nearly as
may be, a pure charge of vapor and assisting
in the expulsion of the remainder of the burned
gases remaining in the cylinder as a result of
the last explosion.

Motors — Two and Three Port. In the two-
port motor, as illustrated in Fig. 133, the func-
tions are as follows:

The first stroke of the piston produces a vac-
uum in the erankcase and the mixture rushes
in (as a conso(iuonce) through the check valve
in the motor case. The second stroke com-
presses the mixture, and when the communicat-
ing port is uncovered the mixture surges into
the cylinder. The next (third) stroke com-
])rosses the mixture entrapped in the cylinder,
since the ports are then covered by the piston,
and at the proper instant the mixture is ignited.

From this point on it is a normal repetition
of functions, and once the motor gets under

The Automobile Handbook

301

way it two cycles. The three-port motor, Pig.
134, differs in that the mixture is taken in
through a third port uncovered by the piston,
instead of through a check valve in the case,
and the details in practice change accordingly.

Fig. 133 Hg. 134

Two-port Motor Three-port Motor

Engine, Gasoline, Fuel Consumption of. The
fuel consumption of a motor is always a serious
question, and one of importance to the pur-
chaser as well as to the manufacturer.

Ordinarily about one and two-tenths pints of
gasoline per horsepower hour under full load
will cover the fuel consumption. That is, when

302 The Automobile Handbook

the mixture is of the proper explosive quality
and the water comes from the jacket at a tem-
perature of about 160 degrees Fahrenheit.

The temperature of the water in the jacket
around the cylinder has a great deal to do with
the fuel consumption.

If the water is forced around the cylinder so
as to keep it cold, the heat from the combustion
is cooled down so quickly by radiation that the
expansive force of the burning gases is mate-
rially reduced, and consequently less power is
given up by the motor.

The object of the water is not to keep the cyl-
inder cold, but simply cool enough to prevent
the lubricating oil from burning. The hotter
the cylinder with effective lubrication the more
power the motor will develop.

Engine, Two-Cycle, Fuel Consumption of.
The two-cycle engine uses more fuel than the
four-cycle. The greatest consumption is not so
much due to the fact that the two-cycle motor
makes an explosion for every revolution, in
contrast with the missed stroke of the four-
cycle, as it is to the fact that there is a consider-
able retention in the cylinder of the exhaust
char<:je, and that, despite the deflector, more or
loss of the fresh charge escapes at the exhaust.
The two-eyc'le is also harder on a battery owing
to 11 H* greater frefjuc^ney of the demands upon
it. but with improved methods of ignition, even
dry batteries have been found to give very sat-
isfactory service.

The Automobile Handbook 303

Enjflite, Sliding Sleeve Type. The Knight
sleeve valve engine, Fig. 135, is a four cycle
gasoline engine in which the usual poppett
valves have been replaced by two concentric
sleeves sliding up and down between the
cylinder walls and the piston. Certain slots in
these sleeves register with one another at proper
intervals, producing openings between the com-
bustion chamber and the inlet and exhaust

^BSiiilf^

^^^V^Lm/

Fig. 135

Kalght Sliding Sleeve Engine
manifolds for the passage of fresh gas into the
cylinder and inirned gas from it.

It will be noted that tbe two sleeves are inde-
pendently operated by small connecting rods

104

The Automobile Handbook

working ' from a shaft made with eeeentrics.
This eccentric shaft is driven at one-half
crankshaft speed, usually by silent chains. This
shaft takes the place of, and performs the same

FiR. 136 Fig. 137

Inlet Openlnp on Inlet Open on

Kulglit Engine Knight Bnglne

notions jis llu> camshaft in the poppett valve
irino. Tlic iH'ivnlrio pins that operate the
mr sK'cvcs arc irivcn a certain advance or
ml over those opcriitinfr the onter Bleeves.
Iii.t Uvul. aboiii 110 degrees, together with the

The Automobile Handbook

half-speed rotation of the shaft, gives the fol-
lowing valve action:

In Pigs. 136 to 142 the relative positions
of the pistons, sleeves and ports are shown in

Fig. 139
Firing Point

various positions during the two revolutions of
the crankshaft that malie up one working cycle
of inlet, compression, power and exhaust
strokes. Fig. 136 shows the inlet just open-
ing. The port, or slot in the inner sleeve is
coming up, the port in the outer sleeve is go-

306

The Automobile Handbook

ing down and the passage for the incoming gas
is formed by the rapidly increasing opening be-
tween the upper edge of the slot in the inner
sleeve and the lower edge of the slot in the

outer sleeve.

Fig. 140 Pig. 141 Pig. 142

Exhaust Opening Exhaust Open Exhaust Cloelag

Fig. 137 shows the inlet fully open. The
inner and outer slots are exactly opposite each
other and the inlet opening in the cylinder
wall. Pig. 138 shows the closing of the in-
let. The cylinder has been filled with fresfa

The Automobile Handbook 307

mixture and is ready for the compression stroke.
Pig. 139 shows the position of the sleeves at
the top of the compression stroke; the com-
bustion space having been completely sealed by
the expansion rings in the cylinder head above
and in the piston below. The firing of the mix-
ture takes place at this point.

Fig. 140 shows the exhaust port just start-
ing to open. The slot in the outer sleeve is
coming up and the slot in the inner sleeve is
going down. Fig. , 141 shows the exhaust
ports fully open. The inner and outer slots
are opposite each other and at the same time
opposite the cylinder opening that leads to the
exhaust piping. Fig. 142 shows the closing
of the exhaust opening and is practically iden-
tical with the position shown in Fig. 136.
The four strokes of the cycle (inlet, compres-
sion, power and exhaust) have now been com-
pleted, the crankshaft has made two complete
revolutions and eac"h sleeve has moved up and
down once.

The timing of inlet and exhaust opening and
closing is not different from that ordinarily used
in poppett-valve engines, but the opening se-
cured with this construction is greater than
that ordinarily found in the poppett type. Some
advantage is also gained because of the more
direct path of the incoming and outgoing gases.
The timing of the valve openings is not affected
by spring pressure or engine speed.

308 The Automobile Handbook

Engines, Eight and Twelve Cylinder Types.

The development of the automobile engine has
been along the lines of increase in number of
cylinders and decrease in the size of the indi-
vidual cylinders, without any considerable in-
crease in the total horsepower delivered by
the engine. This development has resulted in
the power being delivered more evenly, inas-
much as an impulse is delivered to the crank-
shaft each time a cylinder fires. With the sin-
gle cylinder engine, one impulse was given for
each two revolutions and with the increase to
four, six and eight cylinders, the crankshaft
has received two, three and four impulses for
each single revolution. The twelve cylinder
secures a power stroke for each sixty degrees
revolution of the crankshaft and consequently
gives six impulses for each revolution.

The most radical change between former
types of engine and the eight and twelve cylin-
der types is that of placing the cylinders in
two equal divisions, and, in place of standing
vertically, they are placed at an angle of ninety
degrees in the eight and sixty degrees in the
twelve. This design does not materially in-
crease the length of the engine over one having
four or six cylinders of equal size and, of course,
makes the height somewhat less, due to the in-
clination. "While these engines naturally re-
quire additional cylinders, valves, connecting
rods and pistons, they make use of only one

The Automobile Handbook

Fig. 143
Elgbt Cylinder Chassis

310 The Automobile Handbook

crankshaft and generally of but one camshaft.
No other increase in number of parts or ac-
cessories is necessary, one carburetor, one ig-
nition device and one of each of the other
power-plant units doing the work for both sets
of cylinders.

The mounting and construction of the gener-
ally accepted type of eight cylinder engine is
shown in Figs. 143 to 145. As will be noted
from the top view shown in Fig. 143, a space
is left between the cylinder blocks which pro-
vides suitable location for such fittings as the
carburetor, the ignition unit and usually the
lighting dynamo. The valves are located on the
inside of their respective castings and the re-
sulting position of the caps allows easy re-
moval, inspection and grinding.

The center lines of the two cylinder blocks
intersect at the center of the crankshaft, and,
as will be noted from the side elevation in
Fi^. 144, the crankshaft itself does not dif-
fi^v from the usual four-throw type used with
four cylinder engines. Depending on the type
of connecting rod construction used, the cylin-
ders in the blocks are set so that corresponding
ones on opposite sides are exactly opposite or
slijrlitly oflTset from each other in a lengthwise
direction. In any case the connecting rods
from the two front cylinders fasten to one
erankpin, while those from the second cylin-
flers are on the next erankpin, and so on for
those remaining.

Tke Automobile Handbook 311

Fig. 144
I View of Eight Cylinder "V" Type Engine

312 Tks Auiomohile Handbook

Three types of construction are in use for
the lower end of the connecting rods; the most
commoniy used method being shown in Figs. 144
and 145, in which one rod is straight and of

Fig. 145
End view of Eight Cylinder Engine
the usual pattern while the corresponding one
is forked and has the two sides of the fork so
placed that they are on either side of the
straight member. With this construction, the
erankpin is surrounded with a sleeve or liner
of bearing metal and the forked rod is clamped

The Automobile Handbook 313

Fig. 146
Packard Twelve Cylinder Engine

814 The Automobile Handbook

around this liner so that the liner is held
tightly by the rod, and the shaft turns inside
the liner. The end of the straight connecting
rod has its bearing on the outside of the liner
just mentioned and therefore has only a recip-
rocating motion on the liner in place of turn-
ing all the way around. The bearing of the
straight rod on the liner is adjustable, but the

liner is not adjustable on the crankshaft.

Another form of connecting-rod . construc-
tion forms one of the rods in the usual way
with an adjustable bearing on the crankpin.
On the big end of the rod just mentioned is
a boss that carries a pin similar ta a wristpin,
and on this pin is mounted the bearing of the
second connecting rod.. The end of the second
rod does not surround the crankshaft but is
mounted on the end of the one with the beting.

The third form of rod construction is little
used on eight cylinder types, but is quite com-
mon on twelves. This method uses a complete
rod end and bearing on each rod, the ends and
liners being placed side by side so that each con-
necting rod has a bearing on one-half of the
length of the crankpin. The rods are not in
the same plane and therefore the cylinders are
offset, the set on one side of the engine being
a little forward or back of the opposite set.
This method allows individual adjustment of
each ])oaring.

In engines with either eight or twelve cylin-
ders, the camshaft is mounted directly above

The Automobile Handbook 315

the crankshaft and therefore between the cylin-
der blocks. Two designs are in common use,
one making use of separate cams for each of
the sixteen or twenty-four valves, and the other
using but one cam for the inlet valves of op-
posite cylinders and another cam for the corre-
sponding exhaust valves. With but one cam
for two valves, the valve plunger rollers do
not rest directly on the cam, but the plungers
are operated from rocker arms, hinged at one
end to the crankcase and having a roller at the
end that rests on the cam. When individual
cams are used for each valve, the cams are of
necessity placed side by side, but the slight
distance between each pair makes it necessary
to offset the valves or offset the cylinder blocks
in a lengthwise direction.

As mentioned, it is customary to use one car-
buretor with a manifold that divides near the
instrument with one branch for each cylinder
block. Some difficulty was met with in provid-
ing suitable ignition for engines with eight or
twelve cylinders, but this has been overcome
by improved forms of ignition breakers, by the
use of two distributors and two breakers in
some cases and by the adoption of new prin-
ciples of magneto construction in others. When
it is realized that a twelve cylinder engine run-
ning at 1,800 revolutions a minute (a moderate
speed) requires 10,800 accurately timed and
powerful sparks every minute, the reason for
the difficulty will be seen.

316 The Automobile Handbook

ill considering the firing order of these en-
gine's, it should he borne in mind that an eight
is siniihir to two four cylinder engines, side by
side, while a twelve is similar to tw^o sixes. All
four cylinder engines fire in one of two o.rders,
cither 1-3-4-12 or else 1-2-4-3, considering the
front cylinder as number one. Each set of four
cylinders in an eight, that is, the left hand set
and tli(^ right hand set fires in one of these

orders, the only difference with the eight being
tliat one of the cylinders of the left hand set

fires just half way between two on the right,
wiiil(» each cylinder on the right fires midway
between two on the left. The cylinders on
the h'ft, from front to back are usually desig-
nated as Xo. 1 Left, No. 2 Left, and so on;
whih' thos(» in the right are No. 1 Right, No.
2 K'itj^ht, etc. The firing order of a number of
eij^dit cylinder engines is therefore as follows:
IL, 4K^", 3L, 2K, 4L, IR, 2L, 3R; in which it
will ])e seen that, looking at either the **Ls"
or ^'Ks," they fire 1-3-4-2.

The principles explained above apply equally
to the twelve, in which the engine may be con-
sidered as two sixes, each set of cylinders fir-
ing in one of the orders possible for a six. It
is j)ossil)le to number all the cylinders in either
an eight or twelve cylinder engine consecutively
from 1 up and in this case the front right hand
cylinder is usually called number one. The
numbering may then continue from front to
hack on tin* right hand side, in which case

The Automobile Handbook

these cylinders will be numbered from 1 to 6,
or may pass to the left side, calling' the left

Pig. 147
Section Through Twelve Cylinder Engine

front cylinder No. 2, the second one on the
right No. 3, etc. This last method would bring

318 The Automobile Handbook

all the odd numbers on the left and all the even
numbers on the right.

Designating the cylinders of a twelve by the
numbers 1 to 6 and showing their position by
letters, a common firing order would be as fol-
lows : IR, 6L, 5R, 2L, 3R, 4L, 6R, IL, 2R, 5L,
4R, 3L. This fires each set in the common or-
der: 1-5-3-6-2-4.

A twelve cylinder engine is shown in Figs.
146 and 147, and most of the data given in the
foregoing pages applies equally to the twelve
and the eight. The principal difference between
the two types is that the angle included between
the cylinder blocks of the twelve is less than
that of the eight, thus leaving less space be-
tween the blocks in the location often called
the ** valve alley. ^' Because of the smaller
space between the cylinders, a larger one is
left outside of the cylinders before the sides
of the hood are reached. This fact has led to
the practice on twelves of locating the acces-
sories, with the exception of the carburetor,
outside of the cylinder blocks and in the same
place that they usually occupy on four and
six cylinder types.

The Automobile Handbook 319

Ezliaust — Cause of Smoky. Smoke coming
from the exhaust of a gasoline motor is due to
one of two conditions: Over-lubrication — ^too
much lubricating oil being fed to the cylinder of
the motor- or too rich a mixture, that is, too
much gasoline and an insufficient supply of air.

The first condition may be readily detected
by the smell of burned oil and a yellowish
smoke. The second, by a dense black smoke
accompanied by a pungent odor.

Expansion — Best Conditions for. The effi-
ciency of the expansion in an engine cylinder
iepends upon the initial volume of the charge,
;he condition of the mixture, the compression
3ressure, the point of ignition, the speed of ex-
pansion and the losses due to radiation.

The losses due to improper expansion may
therefore be decreased by making large valves
jind valve passages, but these often mean greater
beat losses. The losses due to radiation may
be reduced by increasing the temperature of the
jacket water, and decreasing the area of the
cylinder. But if the cylinder wall temperature
is increased, there are considerable difficulties
with lubrication, and the increased gain in
thermal efficiency will be more than offset by
the increased friction.

In order to obtain the highest efficiency the
difference in the temperature of the water en-
tering and leaving the cylinder jacket should
be a maximum. In practical tests it has been
Edund that the best results are obtained when
the jacket water is near the boiling point.

820 The Automobile Handbook

Flywheels. One of the first and most impor-
tant considerations in connection with the con-
struction of a gasoline automobile motor is the
proper diameter and weight of the flywheel. If
the diameter and weight of the flywheel be
known, the speed of the motor or its degree of
compression will become a variable quantity.
On the other hand, if the speed of the motor
and the degree of compression be fixed, the di-
ameter or weight of the flywheel rim must be
varied to suit the other conditions. If the speed
of the motor and its degree of compression be
known, the diameter of the flywheel or the
weight of the flywheel rim may be readily as-
certained from the following formulas.

Weight of Rims op Flywheels. The weight
of the rim of the flywheel is the only portion
which enters into the following calculations, the
weight of the web, or spokes and hub being
neglected.

Let M.P be the mean pressure of the com-
pression, and A the area of the cylinder in
square inches. If S be the stroke of the piston
in inches, and N the number of revolutions per
minute of the motor, let D be the outside diam-
eter of the flywheel in inches and W its re-
quired weight in pounds, then

M.P X A X S X N
W =

2560 X D
Diameter of Rims of Flywheels. A motor

The AviomobUe Handbook 321

that is- intended to operate at a slow rate of
speed, and consequently with a high degree of
compression, will require a flywheel of much
greater diameter and weight than a high speed
motor of the same bore and stroke. It may be
well to remember that within certain limita-
tions the diameter and weight of a flywheel
should be as small as is possible, as an increase
in either means a reduction in motor speed, and
a consequent loss of power.

To ascertain the diameter of a flywheel
•when all other conditions are known, if D be
the required diameter of the flywheel in inches,
then

M.P X A X S X N

D = :

2560 X W

Weight op Eims of Flywheels with a Given
Fluctuation in Speed. If it be desired to run
a motor at a practically uniform speed and
with only a slight fluctuation or variation in
the velocity of the flywheel, if W be the re-
quired weight of the flywheel and x be the al-
lowable fluctuation of the flywheel in revolu-
tions per minute above and below its normal
speed, then

M.P X A X S X N

W =

365 XX

Horsepower Stored in Rims op Flywheels.
It is sometimes desirable to know the amount of

322 The Automohile Handbook

energy or horsepower which may be stored i
the rim of a flywheel of known diameter an
weight, with a given speed. If H.P be tl
horsepower stored in the rim of the flywhee
then

D2 X W X N

H.F = ^—

792,000

Safe Speed for Eims of Flywheels. The sai
velocity for the rim of a cast iron wheel
taken at 80 feet per second. Let N be sal
speed of the flywheel in revolutions per minut<
then

i8,335

Nnz' —

The mean pressures corresponding to varj
ing degrees of compression may be found b
reference to Table 2.

M.P = Mean pressure.

A = Area of cylinder in square inches.

S = Stroke of piston in inches.

N = Number of revolutions per minute.

D ^ Diameter of flywheel in inches.

W := Weight of flywheel in pounds.

Balancing with the Reciprocating Parts c
THE ]\IoTOR. The flywheel should be balance
as accurately as is possible before mountin
on the crank shaft. In the first place set th
crank sliaft on two perfectly straight paralk
bars, on(^ bar under each end. Then attach th

The Automobile Handbooh 323

connecting rod and piston to the crank and
turn the shaft until the crank jaws are parallel
with the floor, or in other words, at right angles
to a perpendicular line drawn through the cen-
ter of the shaft. Place a scale under the crank
pin, or use a hanging scale attached to some
rigid support above the pin and connect it to
the crank pin by a wire or cord sufficiently
strong to carry the weight. Then find the
weight of the parts according to the scale and
attach the same amount to the flywheel at the
same distance from the shaft on the side oppo-
site the crank, and the result will be a fairly
balanced motor. It is impossible to obtain a
perfect balance, but the above method will
assist greatly in reducing the vibration of the
motor.

While it is true that the weight of the flywheel
may be reduced as the number of cylinders is
increased, there is a practical limit below which
it is inadvisable to reduce the weight at the
rim. Even should the number of cylinders be
sufficient to cause a balance between the work-
ing strokes, it would still be desirable to add a
rotating weight to compensate in some measure
for the several reciprocating masses, such as
pistons, connecting rods, crankshaft webs, etc.
Engines hg,ve been built for racing purposes
without flywheels, but they were unsuccessful.

Friction* Friction, being the resistance to
motion of two bodies in contact, depends upon

324 The Automobile Handbook

the following laws : It will vary in proportion
to the pressure on the surfaces; friction of
rest is greater than friction of motion; the to-
tal friction is independent of the area of the
contact surfaces when the pressure and speed
remain constant; and friction is greater be-
tween soft bodies than hard ones.

The behavior of lubricated surfaces is quite
different from dry ones, the laws of fluid fric-
tion being independent of the pressure between
the surfaces in contact, but it is proportional to
the density of the fluid and in some manner to
the viscosity. When a bearing is thoroughly
lubricated it does not seem to make much dif-
ference what the metals are, because there is a
layer of oil running around with the journal
and sliding over another layer adhering to the
bearing. If, however, the feed fails, or the pres-
sure gets too heavy for the nature of the lubri-
cant, and so squeezes it out, or the temperature
has risen so high as to affect the body of the
oil, then the surfaces come into contact and the
peculiar nature of the contact asserts itself,
some combinations abrading and seizing more
readily than others. When the lubrication is
thorough, the condition of the fluid friction be-
ing realized, the intensity of the load makes less
difference than would be expected. .

Fuels for Automobiles. Apart from the pos-
sibility of an increase in the fuel resources of
the world due to some revolutionary discovery,
the ingredients in any mixed fuel for automo-

The Automobile Handbook 325

bile use must be confined to the following list,
in which, for completeness, gasoline is in-
cluded :

Gasoline. Average composition, C=84, H=:
16.

Source, petroleum.

Boiling point, 50° to 150° Cent.

Specific gravity, .680 to .720.

Calorific value, 19,000 B. T. U.

Latent heat, small.

Benzine. Average composition, 0=92, H
=8.

Source, coal tar.

Boiling point, 80° Cent.

Freezing point, 5° Cent.

Specific gravity, .899.

Calorific value, 19,000 B. T. U.

Latent heat, small.

Alcohol. Average composition, C=32, H=:8,
0=35.

Source, vegetable matter, principally corn,
beets, potatoes, sugar cane.

Boiling point, 70° Cent.

Specific gravity, .806.

Calorific value, 12,600 B. T. U.

Latent heat, considerable.

Tar Benzol. Average composition, C=92,
H=8.

Source, a by-product in the manufacture of
coke.

Boiling point, 80° to 120° Cent.

Specific gravity, .895.

326 The Automobile Handbook

Calorific value, 19,000 B. T. U.

Latent heat, small.

Kerosene. Average composition, C=85,
H=il5.

Source, petroleum.

Boiling point, 150° to 300° Cent.

Specific gravity, .800 to .825.

Calorific value, 19,000 B. T. U.

Latent heat, considerable.

Motor Spirit, Naphtha, Benzoline> Benzine.
Average compositnon, C==85, H=15.

Source, petroleum and shale.

Boiling point, 60° to 160° Cent.

Specific gravity, .750.

Calorific value, 19,000 B. T. U.

Latent heat, appreciable.

Methyl Alcohol, Wood Spirit, Naphtha. Av-
erage composition, C=38, H=12, 0=50.

Source, the distillation of wood.

Boiling point, 66° Cent.

Specific gravity, .812.

Calorific value, 9,600 B. T. U.

Latent heat, appreciable.

Acetylene Ethene. Average composition,
C=92, H=8.

Calorific value, 25,000 B. T. U.

The Automobile Handbook 327

Fuel Peed, Vacuum.

The Stewart vacuum gasoline tank, Figs. 148
to 152, consists of two chambers. The upper
one is the float or filling chamber, and the lower
one is the reservoir or empty chamber. The
upper chamber is connected with the intake
manifold of the motor, and also with the main
gasoline supply tank. The lower or emptying
chamber is connected with the^gaf buretor. Be-
tween these two chambers i^' a valve. The
suction of the piston on the intake stroke creates
a vacuum in the upper chamber. This closes
the valve between the two chambers, and in
turn draws gasoline from the main supply tank.
The gasoline, being sucked or pumped up into
this upper chamber, operates a float valve.
When this valve has risen t6"a certain mark
it automatically shuts off the suction valve and
opens an air valve. This open air valve creates
an atmospheric condition in the upper chamber
and opens the valve into the lower chamber, and

V the gasoline immediately commences to flow to
the lower or emptying chamber. The lower
chamber is always open to outside atmospheric

^ conditions, so that the filling of the upper cham-
ber in no way interferes with an even, uninter-
rupted flow of gasoline from this lower cham-
ber to the carburetor.

A is the suction valve for opening and clos-
ing the connection to the manifold and through
which a vacuum is extended from the engine
manifold to the gasoline tank.

The Automobile Handbook

-j-V> BETOn

Fig, 148
Stewart Vacuum Fuel Peed Tank

The Automobile Handbook 329

B is the atmospheric valve, and permits or
prevents an atmospheric condition in the up-
per chamber. See Fig. 149. When the suc-

tion valve A is open and the suction is drawing
gasoline from the main reservoir, this atmos-
pheric valve B is closed. When the suction

The Automobile Handbook

-trrangement ol Parts ol VacMMm ■Em^l'S*

The Automobile Handbook 331

valve A is closed, then the atmospheric valv^^i

B must be open, as an atmospheric condition is

necessary in the upper tank in order to allow
the fuel to flow through the flapper valve H

into the lower chamber.

C is a pipe connecting tank to manifold of

engine.

D is a pipe connecting vacuum tank to the
main gasoline supply tank.

E is a lever to which the two coil springs S
are attached. This lever is operated by the
movement of the float G.

P is a short lever, which is operated by the
lever E and which in turn operates the valves
A and B.

G is the float.

H is flapper valve in the outlet T. This
flapper valve is held closed by the action of
the suction whenever the valve A is open, but
it opens when the float valve has closed the
vacuum valve A and opened the atmospheric
valve B.

J is a pet cock for drawing water or sedi-
ment out of the reservoir. This may also be
used for drawing gasoline for priming or clean-
ing purposes.

K is a line to the carburetor extended on in-
side of the tank to form a pocket for trapping
water and sediment which may be drawn out
through pet cock J.

L is a channel space between inner and outer
shells, and connects with air vent E, "^ihus main-

332 The Automobile Handbook

taining an atmospheric condition in the lover
chamber at all times, and thereby permittii^
an uninterrupted flow of gasoline to the carbu-
retor.

M is the guide for float.

R is an air veut over the atmospheric valve.
See Pig. 151. The effect of this is the ssiae
as if the whole tauk were elevated and is for
the purpose of preventing an overflow of gaso-
line should the position of the car ever be snch

Fig. 151

Upper Connections of Vacuum Tank
as would raise the gasoline supply tank higher
than the vacuum tank. Through this tube also
the lower, or reservoir chamber, is continually
open to atmospheric pressure, so that the flow
of gasoline from this lower chamber to the car-
buretor is always allowed.

T is the outlet located at the bottom of the

float reservoir in which is the flapper valve H.

The flapper valve is ground on its seat and

Bhould he trouhle-proo?, A. smaft. ■9M\\(iR, «t

dirt getting under the fiappex ^aVift m\^\. -^t^

The Automobile Handbook 333

vent it from seating absolutely air-tight and
thereby render the tank inoperative: In order
to determine whether or not the flapper valve
is out of commission, first plug up air vent;
then detach tubing from bottom of tank to
carburetor. Start motor and apply finger to
this opening. If suction is felt continuously,
then it is evident that there is a leak in the
connection between the tank and the main gas-
oline supply or else the flapper valve is being
held oflf its seat and is letting air into the tank
instead of drawing gasoline.

Any troublesome condition of the flapper
valve can be remedied by removing tank cover,
then lift out the inner tank. Fig. 152. The
flapper valve will be found screwed into the
bottom of this inner tank.

Coupling and elbow connections should be
kept screwed down tight. Care should be taken
that tubing contains no sharp flat bends that
might retard the gasoline flow.

Gasoline for priming or cleaning purposes
can be obtained by opening pet cock.

To make certain that the tank is not at fault
in case of trouble, take out the inner tank en-
tirely. This will leave only the outer shell,
which will then be nothing more than an or-
dinary gravity tank. Fill this tank with gas-
oline and start to run. If you still have trouble
it will be apparent that the fault lies elsewhere
and not in the tank.

334 The Automobile Handbook

Carburetor pops and spits are due to im-
proper carburetor adjustments. Running the
engine at low speed with an open throttle for
any length of time might not produce sufficient
suction to fill the tank when empty. But this
condition might take place because of dirt or
foreign matter getting in and clogging the gas-
oline feed tube.

If you have any doubt as to the tank being
full of gasoline, it is only necessary to close the
throttle and the suction of the motor will then
fill the tank almost instantly.

To fill the tank, should it ever become en-
tirely empty, close the engine throttle and turn
the engine over a few revolutions. This will
create sufficient vacuum in the tank to fill it.
H the tank has been allowed to stand empty
for a considerable time and does not easily fill
when the engine is turned over, look for dirt or
sediment under the flapper valve H, or the
valve may be dry. Removing the plug W in
the top and s(iuirting a little gasoline into the
tank will wash the dirt from this valve; also
wet the valve and cause the tank to work im-
mediately. This flapper valve sometimes gets
a black carbon pitting on it, which may tend
to hold it from being sucked tight on its seat.
Jn this case the valve should be scraped with a
knife.

Tf the motor speeds up when the vacuum tank
is drawing gasoline from the main supply it
shows that either the carburetor mixture is too

The Automobile Handbook

-ich, or the connections are so loose that it is
{rawing air into the manifold. There should

no perceptible change of engine speed when
tank is operating.

336 The Automobile Handbook

Gases, Expansion of. All gases expand
equally, 1/273 part of their volume for each
degree of temperature, Centigrade, of 1/491
part of their volume for each degree of temper-
ature, Fahrenheit.

Gasoline, How Obtained. Benzine, Gasoline,
Kerosene and the kindred hydro-carbons are
products of crude petroleum.

They are separated from the crude oil by a
process of distillation. The process is very sim-
ilar to that of generating steam from 'vtrater.

Crude petroleum subjected to heat will give
off in the form of vapor such products as Ben-
zine, Gasoline and Kerosene, etc. The degrees
of heat at which these products are separated
are comparatively low. Various degrees of heat
will separate the distinct products. As a means
of illustration, it may be said that the crude oil
when raised to certain temperatures gives off
vapors which when cooled liquefy into oils.

Viscosity of Gasoline. It is a mistake to
assume that because gasoline does not thicken
up, it is retarded in its flow through the nozzle
of the carbureter. Taking gasoline having a
specific gravity of 0.71 the quantity that will
pass through the nozzle of a carbureter under a
given pressure will increase as the temperature
is increased, as shown in the following table:

Temp, degrees F. Relative Flow.

F>0« 1

59* 1.073

f?8o 1.145

77» 1.212

86° 1.27

9.«>« 1.886

The Automobile Handbook 337

Since carbureter nozzles are not readily ad-
justable, nor with any degree of certainty, it
follows from the above that the influence of tem-
perature upon the weight of fuel ejected will
most certainly affect the efficiency of the car-
bureter. This source of trouble goes to indi-
cate that some means of maintaining a constant
temperature is of the greatest advantage, and
in a measure it argues for the adaptation of
water (hot) jacketing, not around the depres-
sion chamber, as is usually the practice, but
around the gasoline (float) bowl, in order to
maintain a constant temperature of the liquid
gasoline as it flows through the nozzle.

Gasoline Explosions. There are two entirely
different kinds of explosion, which would un-
doubtedly both be referred to as gasoline ex-
plosions. The real gasoline explosion is the
kind taking place in the cylinder of a gasoline
motor, in which heat and pressure are suddenly
produced by the combustion of gasoline vapor
in air. The other kind of explosion referred to
may be explained as follows:

If a tank of gasoline be placed on a woodpile
and the latter set on fire, the heat would
raise a pressure in the tank, which would rap-
idly increase and the tank would finally explode
from the pressure. The gasoline would then
be thrown in all directions, and, owing to its
superheated condition, the greater part of it
at least would instantly vaporize, mix with the

338 The Automobile Handbook

air of the atmosphere and be ignited by the
flame which caused the explosion.

Gasoline Fires, Extinguishing. A number of
fires have been caused by leaky gasoline pipes
on automobiles, and many persons would like to
know of chemicals which can be used to put
out such fires. Water is exceedingly danger-
ous to use, and it is not always possible to get
at the fire to smother it with wet rags or waste.

In case of fire due to gasoline, use fine earth,
flour or sand on top of the burning liquid.

A dry powder can be used for this purpose
which will extinguish the fire in a few seconds.
It is made as follows : Common salt, 15 parts —
sal-ammoniac, 15 parts — bicarbonate of soda,
20 parts. The ingredients should be thoroughly
mixed together and passed through a fine mesh
sieve to secure a homogeneous mixture.

If by any chance a tank of gasoline takes fire
at a small outlet or leak, run to the tank and
not away from it, and either blow or pat the
flame out. Never put water on burning gaso-
line or oil, the gasoline or oil will float on top
of the water and the flames spread much more
rapidly.

Several gallons of ammonia, thrown in the
room with such force as to break the bottles
which contain it, will soon smother the strong-
est fire if the room be kept closed.

It is not advisable to operate a pleasure car,
and certainly not a truck, without having a port-
able extinguisher on the car. Such extinguish-

The Automobile Handbook 339

ers are made in sizes suitable for carrying in an
easily accessible place and should be so mounted.
A fire starting in the under-pan or under the
hood may be smothered in the beginning, while
delay would mean the car's destruction.

Gki,soline, Thermo-dynamic Properties of
Gasoline and Air. The. following table, 8,
gives the thermo-dynamic properties of gaso-
line and air, and may be of interest, in view of
the fact that information on this subject is
sparse, and most of that only theoretical, or
empirical deductions.

This table gives the explosive force in pounds
per square inch of mixtures of gasoline vapor
and air, varying from 1 to 13 down to 1 to 4,
also the lapse of time between the point of igni-
tion and the highest pressure in pounds per
square inch attained by the expanding charge
of mixture. The tests from which the results
given were obtained, were made with a charge
of mixture at atmospheric pressure, so as to
more accurately note the results, as the mixture
takes much longer after ignition to attain its
highest pressure, and is slower also in expand-
ing.

It may be well to remember that there are no
more heat-units, and consequently no more foot-
pounds of work in a mixture of gasoline and air,
under 5 atmospheres compression, than under
1 atmosphere compression.

Flanged or ribbed air-cooled motors will ap-
proach the figures given in the table for the

3^0

The Automobile Handbook

initial explosive force for the varying con
sions, very closely, while thermal-siphor
ter-cooled motors will come within abo
per cent of these results, and pump and rj
ing coil cooled motors will come within
30 per cent. While it appears at the first g
that the proper thing to do to get the gn
efficiency from a motor would be to let i
as hot as possible, experience has shown
the repair bill of a hot motor will more
offset its efficiency over the cooler water
eted motor, with pump and radiating coils
last two columns in the table give the ten
ture of the burning gases, the first of th(
eohimns the actual temperature with th
companying mixture of gasoline and air
the second the theoretical temperatures, or
peratnre to which the burning mixture si
attain, if there were no heat losses.

TABLE 8.

THER^rO-PYXAMIC FROFERTIES OF GASOLIXS AND A

Air.

I i.> n

1 to

1 '■>

1 r .

Time in

betwtva
Ignition

and

Ui^iht'st

Vrt-

surt'. *

0.07

Explosive Force in
Pounds per sq. in.

Compression
ia Atmospherei.

•J TO

lUO

Temper

of Comb

in Des

Fahren

ActoaL

18."»7
2196
280:^
3110
3226
2965

•A: at!"'

-■^snrtv

The Automobile Handbook 341

Oearless Transmission. This name has been
applied to a wide variety of transmission, or
change speed devices. It is quite customary to
refer to the friction drive as a gearless system,
and this is true to the extent of not using
toothed gearing of any form.

A car using this name was built several years
ago, and its construction embodied a novel
method of change speed mechanism. The trans-
mission system of the gearless car made use of a
central cone, long in proportion to its diameter,
and faced with friction material. Placed so that
they might engage with this driving member,
were several sets of rollers, which were, in turn,
brought into contact with driven members or
clutches. The principle of operation was that
of the planetary, or internal epicyclic, gear. In
place of using toothed gears, this car secured its
drive by bringing one or the other sets of rollers
into play and thereby secured three forward
speeds and one reverse. Large power was trans-
mitted and little trouble found.

Gears, Diametrical Pitch System of. Table
9 gives the necessary dimensions for lay-
ing out and cutting involute tooth spur gears
from No. 16 to No. 1 diametral pitch. Formulas
are also given so that if the number of teeth
and the diametral pitch are known, the pitch
diameter can be ascertained — also, the diam-
etral pitch, outside diameter, number of teeth,
working depth, and clearance at \>o\Xot£v c^'i
tootb :

342 The Automobile Handbook

P =: Pitch diameter in inches.
D = Diametral pitch.
W = Working depth of tooth in inches.
T = Thickness of tooth in inches.
0 = Outside diameter in inches.
C ^ Circular pitch in inches.

(1) Pitch diameter=^ —

(2) Outside diameter=P-| —

(3) Diametral pitch = —

3.142

(4) Circular pitch=:

( 5 > Working depth of tooth= — =2-^.

(()) Xumher of teeth=PxD

(7) Thickness of tooth=1.57lXl

( S 1 Cloaranc'o at bottom of tooth= —

For oxani]^l(^ : "Required, the pitch diamet(
of a irear with 20 teeth and No. 5 diametn

The Automobile Handbook

343

pitch. From Formula No. 1, as the pitch diam-
eter is equal to the number of teeth divided by
the diametral pitch, then 20 divided by 5
equals 4, as the required pitch diameter in
inches.

What is the outside diameter of the same
gear? From Formla No. 2, as the pitch diam-
eter is 4 inches, and the diametral pitch No.
5, then 4 plus 2/5 equals 4 2/5 as the proper
outside diameter for the gear.

What would be the diametral pitch of a
gear with 30 teeth and 5 inches pitch diame-
ter? From Formula No. 3, 30 divided by 5
equals 6, as the diametral pitch to be used for
the gear. In this manner by the use of the
proper formula any desired dimension may be
obtained.

TABLE 9.
DIMENSIONS OF INVOLUTE TOOTH SPUB GEABS.

Diametral
Pitch.

Circular
Pitch.

Width of

Tooth on

Pitch

Line.

WorkinL

Depth o

Tooth.

Actual

Depth of

Tooth,

Clearance
at Bottom
of Tooth

3.142

1.571

2.000

2.157

1.571

0.785

1.000

1.078

1.047

0.524

0.667

0.719

0.785

0.393

0.500

0.539

0.628

0.314

0.400

0.431

0.524

0.262

0.333

0.360

0.447

0.224

0286

0.308

0.393

0.196

0.250

0.270

0.314

0.157

0.200

0.216

0.262

0.131

0.167

0.180

0.224

0.112

0.143

0.154

0.196

0.098

0.125

0.135

0.157
0 078
0.052
0.039
0.031
0.026
0.022
0.019
0.016
0.013
0 011
0.009

(Jears, Horsepower Transmitted by. The fol-
lowing formulas will give the horsepower that

344 The Automobile Handbook

may be transmtited by gears with .cut teet"
involute form and of various metals.

H.P 1= Horsepower.

P = Pitch diameter in inches.
C = Circular pitch in inches.*
F = Width of face in inches.
R 1= Revolutions per minute.

PXCXFXR

XJ..X —

PXCXFXR

H.P-

140

PXCXFXR

H.P-

410

TTT>

PXCXFXR

(Annealed tool steel.)

(Mach. steel or Phos-
phor Bronze.)

(Cast Brass.)

(Cast Iron.)

550

Example: Required, the horsepower wl
a tool steel pinion, 2 inches pitch diamete
inch face and No. 10 diametral pitch,
transmit at 900 revolutions per minute.

Answer: From the table the circular p
oorrespondinfi: to No. 10 diametral pitch

*The circular pitch corresponding to any diametral pitch :
bcr. may be found by dividing the constant 3.1416 by the c
etral i>i'tch.

Kxamplo: What is the circular pitch In Inches correspon
to No. <) diametral pitch.

Answer: The result of dividing 3.1416 by 6 gives 0.524 Jb
as the required circular pitch.

The Automobile Handbook

345

0.314. Then by Formula No. 1, 2X0.314X1X
900 equals 56&.2. This, divided by 90, gives
5.29 horsepower.

Gear, Intemal-Epicyclic. It is often desired
to ascertain the speed of rotation of the differ-
ent members of this form of gearing. To cal-
culate their speeds, the following formulas are
given, which, by reference to the letters desig-

Fig. 153

nating the different parts in Figure 153, may be
readily solved.

Let R be the revolutions per minute of the
disk or spider carrying the pinions D.

Let N be revolutions per minute of the gear
E.

Let 6 be the revolutions per minute of the
internal gear F.

When the internal gear F is locked and gear
E rotating, the speed in revolutions per minute
of the disk or spider carrying the pinions D is

346 The Automobile Handbook

E
R = N

E + F

If the internal gear be locked and the spider
carrying the pinions D be rotated, then the
speed in revolutions per minute for the gear E
will be

E + F
Nz=R

If the spider carrying the pinions D be held
rigid and the gear E be rotated, the speed in
revolutions per minute for the internal gear F ia

NXE

G = ^

If the pitch diameter of the gears is not read-
ily obtainable, the number of teeth in each gear
may be used instead, as the result will be ex-
actly the same.

It will be recognized that this is the form of
gearing employed in the older forms of plane-
tary transmission devices. Newer types use no
internal toothed gears.

Heat of Combustion. The quantity of heat
generated by the complete combustion of vari-
ous gases and petroleum products is known
as the heat value of the fuel, and represents the
maximum amount of heat that can be obtained
from a given quantity of the fuel. No accurate

The Automobile Handbook 347

rule has yet been devised by which to compute
the heat vahie of any chemical compound from
its formula and the heat values of the elements
of which it is composed. Hence, the heat values
of compounds must be found by a separate de-
termination for each one in the laboratory. The
heat developed by the combustion of some of
the commoner fuels and gases is given in Table
14. In the case of carbon, the heat developed
by its complete combustion, forming CO2, and
the heat of its partial combustion to CO, are
given; also the heat of combustion of CO to

CO2.

Heat Value op a Mixture. The heat value
of a mixture may be found from the heat val-
ues of the substances of which it is composed
and the percentage of each substance. If h^,
ha, hs, etc., represent the heat values of the
substances forming the mixture, and Pi, P2, Ps,
etc. represent the percentage of each substance,
the heat value of the mixture will be repre-
sented by the following formula :

hm=Pihi+p2h2+P3h3+etc.

Example. — A certain gas has the following
composition :

Constituents of Oas Per Cent.

Hydrogen, H 20

Marsh gas, CH4 70

Acetylene, C2H2 10

What is the heat value per cubic foot of the
mixture ?

Solution. — Referring to Table 10, the heat

348

The Automobile Handbook

■

•04

•k » » » flk

fid

•3

S^S

K » ■» » »

C4C4^e><

:S^

C4 esl-

SB
O

Ik
O

5 •«

Hip i

:§

:S :
:S5 :

i7'.46
14.90

:8 :

• • • •

•

• Oec •

■ • • ■

• •
■ •

• 00 •

•

•■^« •

• •

■^

OO
CO

09 0QSt>0»

ta04» • •

• • • lO ph

9'«<OC0'H

'to

■ OOtO tOiO

■ 04 cQ cQ to' e><

e
04

00 isS

eco»

^00

lO
lO

00 CO ec 04^^
e4<-^ v^ *^

t^S

»H O40O

Q0 04 04^'«CO
OtHtH tH

Jk S3'-s_S

^ ^

»* »*04

04 ^«0

o> ab>o

S &8

d C4C0^SSlo
t«. eo»o

O »mO©

•o

•31
- II

04 04

o
WoSo«

(O n II ■• ■

)(0 I H I -^ I

t s9e§s

OS5

i> cf d* a d

>>«i c3 cS a

Koouo

S S s-i J

The Automobile Handbook 349

values per cubic foot of these gases are seen to
be 327, 1,010 and 1,464 B. T. U., respectively.
Apply the formula just given, p^ = .20, Pg =
.70, and pg = .10. Also, hj = 327, h^ = 1,010,
and hg = 1,464. Substituting, hm = .20 X 327
+ .70 X 1,010 + .10 X 1,464 = 65.4 + 707 +
146.4 = 918.8 B. T. U. Ans.

Temperature op Combustion. The theoret-
ical temperature of the combustion of a given
fael can easily be calculated. Making no al-
lowance for losses of heat, and supposing that
just enough air is furnished for the combustion,
burning carbon should have a temperature
about 4,940° above zero ; while burning hydro-
gen should have a temperature about 5,800°
above zero. In practice, these temperatures
are never attained, on account of heat losses.

Loss OP Heat. The loss of heat from any hot
object is accomplished in three ways: by con-
vection, by conduction and by radiation. In
all practical cases a body loses heat by a com-
bination of these processes.

When heat is produced in the cylinder by the
combustion of the gases, the piston is at or near
the upper dead center ; that is, it remains nearly
stationary when the heat is greatest and when
the heat loss per unit area of inclosing walls is
most rapid.

Under the usual conditions of ignition, the
gas contained in the cylinder must be set into
violent motion by the spread of the flame
through it, and this motion will aid the dissipa-

350 The Automobile Handbook

iion of the heat in the gas to the containing
walls. So convection will be an important fac-
tor in the process and perhaps the principal
factor. Perhaps a part of the gain in power
which has resulted, in some instances, from the
use of multiple ignition may be due to violent
motion of the gas. Practically all air cooled
motors have their valves in the head, so the
charge is contained between the cylinder walls
and the piston head.

The heat absorbed by the water-jacket is
equal to the weight of water passed through the
jacket multiplied by the temperature range ; or,
in other words, it is the difference between the
temperature of the water when it enters the
water-jacket and that of the water when it
leaves the jacket. For instance, if the tempera-
ture of the entering water is 50** and that of
escaping water is 180°, the temperature range
is 180°— 50** =130°. Then, if the weight of
the water passing through the jacket in 1 hour
is 100 pounds, the heat carried away is 100 X
130 == 13.000 British thermal units.

Horsepower. The actual horsepower of an
engine can only be determined by making a
test with suitable brakes or dynamometers.
This method would give the actual brake horse-
power. In order to allow ready calculation, the
Society of Automobile Engineers' formula is
used and is generally recognized. The bore or
diameter of the cylinder is first squared; that
is, the size in inches is multiplied by itself. This

• The Automobile Handbook 351

number is then multiplied by the number of
cylinders and the result divided by 2i/^. Thus,
for an engine with 5-inch bore: 5x5=25. If
of 4 cylinders, 25x4=100, and 100 divided by
2% gives the result as 40 horsepower. In order
to secure approximately correct results, the en-
gine is supposed to be operating at 1,000 feet
per minute piston speed.

Horsepower of Explosive Motors. The first
requisite is to find the number of power strokes
made per minute by the motor. In a single
cylinder motor of the four-cycle type there is
one power stroke for every two revolutions,
and if the motor has four cylinders there is
one power stroke for every revolution of the
crank shaft. The number of power strokes then
may be found by the following formula (refer-
ring to a four-cycle motor) :

N = — XS

in which N = Number of power strokes per

minute.

C = Number of cylinders.
S = Angular velocity of crank shaft in rev-
olutions per minute.

Having ascertained the number of power
strokes per minute, the horsepower is found by
the formula,

PLAN

H.P =

33,000

352 The AviomobUe Handbook

P = Mean effective pressure (M. E. P.).

L = Length of stroke in feet.

A = Area of piston in sq. in.

N = Number of power strokes per minute.
This formula does not discriminate betwe
mechanical friction and losses in ** fluid'' fr
tion. A formula that is more arbitrary a:
that fits the majority of cases, requiring or
the use of a few facts, such as diameter of c:
inder, length of stroke, and revolutions per m
ute, is presented as follows:

VXN

H.P =

10,000

in which

V = volume of cylinder in cu. inches.
N = number of power strokes per min.

The constant used varies from 9,000 to 14,0
depending upon certain types of engines; 10,0
bein^ an average figure for four cycle engint
Tlie brake horsepower will be from 65 to 85 p
cent of the result obtained ; 80 per cent may
taken as an average. As an example we mi
lake a four-eycle, four-cylinder motor 4V^i
bore and -^Y^-m. stroke making 1,200 pow
str()k(^s i)er minute. Volume (V) of eylind
ecjuals area of piston 15.9 sq. in. X length
strokes 414=71.55 cu. in., and multiplying tl
by 1,200 (N) and dividing the product by 1
000 trives 8.05 IT.R Taking 80 per cent of tl
as the brake horsepower the result is 6.44 H

The Automobile Handbook 353

From a theoretical standpoint a two-cycle ex-
plosive motor should not only have as great a
speed, but also be capable of developing almost
twice the power that a four-cycle motor does.
It is a fact nevertheless that its actual perform-
ance is far different.

The horsepower of a two-cycle motor may be
calculated from the following formula,

D^XSXN

H.P=

21,000
in which

I>^diameter of cylinder in inches.
S=stroke of piston in inches.
N=number of revs, per minute.

Example : Required, the horsepower of a two-
cycle motor of 4:y2 inches bore and stroke, with
a speed of 900 revolutions per minute.

Answer: The square of the bore multiplied
by the stroke is equal to 91.125, which multi-
plied by 900, and divided by 21,000, gives 3.91
as the required horsepower. The results given
by the above examples agree very closely with
those obtained from actual practice.

Horsepower, Electrical. One electrical horse-
power is equal to the current in amperes multi-
plied by the electro-motive force or voltage of
the circuit and divided by 746.

Let C be the current in amperes and E the
voltage of the circuit. If E. H. P. be the re-
quired electrical horsepower, then

354 The Automobile Handbook

EXC
E.H.P=

746

In practice with motors of small power, 1,000
watts are necessary to deliver one mechanical
or brake horsepower at the driving shaft of the
motor.

If the actual or brake horsepower of an elec-
tric motor be known, the eflSciency of the motor
may be readily found by the following formula :

If E be the voltage of the circuit and C the
current in amperes consumed by the motor, let
B. H. P be the brake horsepower of the motor
and e the eflSciency of the motor, then

B.H.P X 746

e =

EXC

Table 10 gives the electrical horsepower of
motors with voltage from 20 to 100 volts, and
current strengths from 10 to 80 amperes.

The mechanical eflSciency of a motor may be
found by use of the table as follows

Example: Required the mechanical eflSciency
of a 40-volt, 60-ampere motor, which is rated
b3' its maker as of 3.25 horsepower — ^the motor
when under full load using 80 amperes.

Answer : Reference to the column in the table
corresponding to 40 volts and 60 amperes gives
3.22, while the 80 ampere column gives 4.29.
Then 3.22 divided by 4.29 gives 0.75, or 75 per
cent, as the mechanical eflSciency of the motor.

■ The Automobile Handbook 355

Ignition STstrane.

Ignition. Id order that an explosive motor
lay operate economically, and with the highest
ere en t age of efficiency, it is absolutely neces-
iry that two objects shall be attained, viz.: A

Fig. 154
Doll and Timer Ignition With Storage Battery

irrect mixture of the gasoline and air, and that
lis mixture be correctly ignited at the proper

Tke Automobile Handbook

Fig. 15B

Coll and Timer With Dry Cells. A, Switch. B,
Dry Cells. C, Condenser. D, Timer. E, Con-
tacU. F, Armature. O, Core ot Coll. H, Pri-
mary Winding. I, High Tension Winding. J,
Spark Plug.

Coll Vibrator Principle. A, Core of Coll. B, Arma-
ture ot Coll Magnet. C, Adjusting Screw. D^
Trembler Blade. E, Contacts.

The Automobile Handbook

357

Fig. 157

Coil Vibrator Details. A, Adjustment. B, Tension
Spring. C, Trembler Blade. D, Holding Screw.
E, Contact Bridge. F, Contact Blade. G, Lock-
ing Screw,

358

The Automobile Handbook

EMERGENCY
BATTERY OF
6-ORY CELLS

STORAGE
BATTERY

Fig. 158
Connecticut Storage Battery Ignition Wiring

iCnmoN dWTCH

antrs0e

itmtton

COIL

Fig. 159
Circuits Through Remy Battery Ignition Syatai

The Automobile Handbook

359

Induction Coil. Induction is the process by
which a body having electrical or magnetic
properties calls forth similar properties in a
neighboring body without direct contact. This
property is known as self-induction, and is
caused by the reaction of different parts of the
same circuit upon one another, due to varia-
tions in distance or current strength. The cur-
rent produced by an induction coil has a very
high electro-motive force, and hence great
power of overcoming resistance.

/*•% /'♦x /"x .'

■J-»-

-»—-

i4-

-*-♦>:

*— ' **.'' ^.•' ^^^

SWITCH - + BATTER^

■ If

-»-

( \. M t\ f\ f
\ ' •* ^-^y ••• *•*'

SWITCH ♦ -^

INDUCTION COIL

Pig. 160.

If a current of electricity be caused to flow
through a straight conductor forming a part of
a closed electric circuit, lines of force, com-
monly called magnetic whirls or waves, are in-
duced in the air and rotate around the conduc-
tor.

If the current of electricity be flowing in the
circuit and through the straight conductor from

360 The Automobile Hmdbook

right to left, as shown in the upper view in Fig.
160, the lines of force or magnetic whirls will
rotate around the conductor from left to right,
or in the direction of the hands of a clock. On
the other hand, if the conditions be reversed
and the current flows from left to right the lines
of force or magnetic whirls will rotate from
right to left, as shown in the lower view in Fig.
160. The direction of rotation of these lines
of force or magnetic whirls may be positively
determined by the use of a galvanometer, an
electric testing instrument having a needle simi-
lar in appearance to that of an ordinary com-
pass. Upon placing this instrument in the
path of the lines of force and making and
breaking the battery circuit by means of the
switch, the needle of the galvanometer will be
deflected from its zero point in the direction of
the rotation of the lines of force. If the direc-
tion of the flow of the electric current through
the circuit be changed by reversing the poles of
the battery, the needle of the galvanometer will
be deflected from its zero point in the opposite
direction. Whether these lines of force or mag-
netic whirls rotate continuously around the wire
has not been demonstrated. They rotate with
sufficient force to be tested by the galvanometer
only until the electric current in the closed
circuit has reached its maximum value after
closing the circuit; that is to say, only during
the infinitesimal space of time required by the
current to reach its full value or power.

The Automobile Handbook

361

If, instead of a straight conductor, a loop of
insulated wire, in the form of a circle, be until-
ized for the passage of the current, as at A and
B in Fig. 161, the lines of force will still rotate
aVound the wire as shown, their direction being
dependent on the direction of the electric cur-
rent. If the electrical circuit be provided with

Fig. 161

a current reverser, or device for changing the
battery connections in the circuit from positive
to negative and vice versa, the lines of force can
be made to rotate rapidly first in one direction
and then in the other, as indicated in Fig. 160.
Suppose this loop of insulated wire be com-
posed of a great number of turns, it then be-

362 The Automobile Handbook

comes a coil or closed helix, and as all the lines
of force cannot pass between the turns of the
electrical conductor forming this helix they
must pass completely through the helix instead
of rotating around a single loop, as at A and 6,
Fig. 161. If the current flows through the con-
ductor in the direction indicated by the ar-
rows, at C in Fig. 161, and over and around the
coil in the direction shown, the lines of force
will flow through the coil towards the observer,
and complete their path or circuit through the
air, returning into the coil at the opposite end.
If the current be reversed and flow around the
coil in the direction of the hands of a clock, the
lilies of force will flow through the coil in the
opposite direction, that is, away from the ob-
server, as at D, Fig. 161.

This form of coil or closed helix may be des-
ignated as the primitive form of an electro-
magnet. "When forming part of a closed elec-
tric circuit it possesses the property of magnet-
izing a bar of wrought iron placed within it.
If a short round bar of wrought iron be placed
a short distance within the coil, and the battery
circuit be closed, the iron bar will, if the cur-
rent is sufficiently strong, be sucked or drawn
into the center of the coil, and a considerable
effort will be required to withdraw it.

The object of the bundle of soft iron wires,
which form the core of any form of spark coil,
is to increase the magnetic effect of the lines of

The Automobile Handbook

363

force or magnetie flux, or rather to reduce the
resistance to their passage through the coil.

As has been previously stated, when a current
of electricity flows through a conductor of wire
forming a coil or closed helix, Jines of force are
induced and flow through, and also around the
exterior of the coil. In a like manner, when the
electric circuit is broken, the lines of force sud-
denly reverse their direction, and travel through
the coil with a tremendous velocity until they

Fig. 162
Principle ol Atwater Kent Battery Ignition

reach a state of neutralization. During this re-
verse travel of the lines of force through the
coil, a current of electricity is induced in the
vpinding of the coil, but in the opposite direction
to that in which the battery current was flowing.
The effect of this induced current, which is of
far greater intensity or pressure thaii the bat-

The Automobile Handbook

. The Automobile Handbook 366

tery current which induced it, is to form an arc
or spark at the breaking point in the circuit.

Secondary Spark Coil. Fig. 163 shows the
secondary or jump-spark form of coil. It is
composed of an iron core and a primary winding
similar to that described in conjunction with
Fig. 162, with the addition of an outer winding
of many turns of fine wire. This wire, of very
small size, is known as the secondary winding,
varying in diameter from No. 36 to No. 40 B. &
S. Gauge, and in length from 5,000 to 10,000
feet. In the drawing the induction coil is
shown equipped with an electro-magnet make
and break, or vibrator device, which is the form
mostly used for ignition purposes. The other
form, known as the plain jump-spark coil, has a
mechanically operated make and break device
attached to the motor to operate the coil.

The arc or spark produced at the breaking
point of the electrical circuit in which the pri-
mary winding of the coil is connected is not
utilized for ignition purposes in this type of coil.
When the circuit is broken the sudden reaction
or backward flow of the lines of force or mag-
netic flux in the iron core produce an induced
current in the secondary winding, but in the
opposite direction to that of the battery cur-
rent. This induced current is of so much
greater intensity and velocity than that induced
in the primary winding by this same reaction,
that the arc or spark induced in the secondary
winding of the coil will jump across a space

366 The Automobile Handbook

from one end of the wire to the other, varj
from Ys inch to as much as 8 or 10 inche
length, dependent upon the length of wir(
the secondary circuit, the electro-motive f(
of the battery and the frequency of the in
ruptions or number of times per minute
electric circuit is made and broken.

Referring to Fig. 163 A is the core, B the
mary winding and C the secondary. The
coils are held in place upon the core by
washers D. The primary wire B is wound (
a paper tube E, and the secondary wire C is
sulated from the primary wire by a mica ii
lating tube F. The coil proper is enclosed
wood case G.

The terminals or binding posts on top of
case G are connected with the ends of the
ondary wire 1 and 2. The secondary termi
are plainly indicated by the letter S*. In
base H of the coil case is the condenser J,
essential feature of this form of coil, wJ
utilizes the induced primary current to* prod
a greater reactive energy in the second
winding.

At the right-hand end of the coil and oufc
the casing G is located the electro-magnetic
brator or trembling device, which automaticj
makes and breaks the primary circuit. 1
end 3 of the primary wire is connected with '
contact screw K through the bracket L. 1
spring M, carried by the bracket N, with ser
0, is connected with the terminal or bindi

The Automobile Handbook 367

post P, immediately beneath it, by the wire 6
through the bracket N. The end 4 of the pri-
mary wire is connected with another terminal
or binding post P, at the other end of the base
of the coil. The condenser J is connected
across the contact points of the screw K and
the spring M, by the wires 5 and 6 and screws
Q and X. The condenser is composed of a num-
ber of sheets of tinfoil V, laid between sheets
of specially insulated paper I, with the opposite
end of every alternate sheet of tinfoil projecting
from the paper insulation, as shown. These
projecting ends are connected together, and by
the wires 5 and 6 to the contact screw K and
spring M, respectively, as previously described.
When the coil is connected in, or forms part
of a closed electric circuit by means of the ter-
minal or binding posts P, on the base of the
coil, the current flows through the primary
winding B. This instantly produces a high de-
gree of magnetism in the core A, and the pole-
piece T of the core extension R becomes strongly
magnetic and attracts the iron button W of the
spring M. This draws the spring M away from
the end of the screw K, and in consequence
breaks the electric circuit. This results in the
demagnetizing of the pole-piece T and the con-
sequent return of the spring M to its normal
position in contact with the end of the screw K.
So long as the electric circuit remains closed
this operation is repeated at a very high rate
of speed. The effect of this continuous opera-

368 The Automobile Handbook

tion of the coil is to produce an intermittent
current in the secondary winding of high inten-
sity and velocity. If wires are placed in the
holes in the small terminals or binding posts on
the top of the coil and brought within a short
distance of each other, a stream of sparks will
pass from one wire to the other in a peculiar zig-
zag manner and emit a loud, crackling noise,
accompanied by a peculiar odor, caused by the
formation of ozone through the electro-chemical
action of the spark.

Under ordinary circumstances the arc or
spark which occurs on the breaking of the con-
tact between the platinum points of the screw
K and spring M would not be utilized, but by
means of the condenser in the base, which is
connected to these parts, as before described,
the static charge of electricity generated by this
action is stored in the condenser. When the
contact is again made this stored electric energy
is given up or discharged by the condenser and
flows through the primary winding of the coil
in connection and in the same direction as the
battery current and increases the magnetic ef-
fect of the core A enormously.

The construction and operation of the con-
denser is fully described under the heading
Condenser, It should be understood that this
is one of the most important elements of the
ignition system, whether battery or magneto
type, and its care should never be neglected if
eflfident ignition is desired.

The Automobile Handbook 369

Ignition — Timing. In timing the ignition of
a motor one should base his operations on one
particular cylinder, and this should be the most
accessible one. Let it be assumed that a me-
chanic is required to test or correct the timing
of a four-cyli^der, four-cycle vertical engine.
He would have to know. the order in which the
cylinders fired, and how to find the firing center
of No. 1 cylinder. As the operation of the
valves on most motors may be readily seen, the
firing center and the order in which the cylin-
ders fire can be easily learned from the action
of either set. For instance, if on turning the
motor over slowly the intake valve of No. 1
cylinder opens and closes, then that of No. 3
cylinder, and following No. 3 that of No. 4 op-
erates, the mechanic need go no further, for he
knows that the engine fires 1-3-4-2. The ex-
haust valves, of course, may be used in the same
way. However, if the valves are entirely en-
closed, as on the Winton cars, open the priming
or relief cocks, and beginning with cylinder No.
1 note the order in which the air is forced out
through the cocks. There are two rules for
finding which cylinder is on its firing center,
that are based on the action of the valves ; these
are as follows: When an exhaust valve is open
the following cylinder is about to fire. When
an intake valve is open the previous cylinder is
about to fire. One very simple method of find-
ing the firing center of a cylinder is to open
the priming cocks of all the cylinders but one.

37(> The Automobile Handbook

turn the motor over slowly till compression is
encountered, open the cock, insert a stiff wire
till it rests on the piston head, then carefully
bring the piston to the top of its stroke. The
cylinder will then be on its firing center. "When
the firing center, and the order in which the cyl-
inders fire are known, all that remains to be
done in timing an engine is to set the revolving
segment of the commutator or distributer so
that a spark will occur in the proper cylinder
when the spark control lever is advanced about
one-third or, with the spark control lever fully
retarded, and the piston about i/^ to 1 inch
down on the explosion stroke, set the segment
so that it just begins to make contact.

Many troubles arise from faulty or defective
insulation.

A wire placed too close to an exhaust-pipe
invariably fails after a time, owing to the insu*
lation becoming burnt by the heat of the pipe.

A loose wire hanging against a sharp edge
will invariably chafe through in course of time.

If the insulation of the coil breaks down it
cannot be repaired on the road, it should be re-
turned to the makers. A slight ticking is
usually audible inside the coil when this occurs.

All wires where joined together should be
carefully soldered, the joints being afterwards
insulated with rubber or prepared tape. Never
make a joint in the secondary wires. See that
all terminals are tightly screwed up. When
connecting insulated wire, the insulation must

The Automobile Handbook 371

be removed, so that only the bare wire is at-
tached. Wires sometimes become broken, and
being loose make only a partial contact.

Battery terminals frequently become cor-
roded ; they should be covered with vaseline,
and require periodical cleaning. See that all
connections at the battery are clean and bright.

The porcelain of the spark plug may be
cracked and the current jumping across the
fracture. The points may be sooty and require
cleaning. They may be touching and require
separating, or they may be too far apart. The
usual distance between the points is about one
thirty-second of an inch, which is approxi-
mately the thickness of a heavy business card.

Clean all oil and dirt from the commutator.
Most commutators are so placed as to give the
maximum possible opportunity to collect oil
and dirt. They should always be provided with
a cover.

In course of time dry or storage batteries
will become weak or discharged. Always carry
an extra set.

Spanners, oil-cans, tire-pumps, etc., have been
known to get on the top of the batteries,
thereby connecting the terminals together and
causing a short-circuit.

The platinum contacts of the coil may be-
come corroded. They should be cleaned with a
small piece of emery cloth or sandpaper.

372 The Automobile Handbook

Ignition, Atwatcir Kent. This device is de-
signed to draw from a battery, as nearly as
possible, only the electrical energy necessary
to ignite the charge, and to keep the batteries
until the energy remaining in them is too small
to produce an effective spark. Its principal
constituent parts are, a jump-spark coil and
condenser, a primary contact maker, the time
of which may be advanced or retarded, and a
high tension distributer. Its distinguishing
features are —

a. But one spark is made for each ignition.

b. The primary contact, rupture of which
produces the spark, is exceedingly brief,, no
longer in fact than is actually required to build
up the magnetism in the core of the spark coil.

c. The duration of this contact is independ-
ent of the engine speed in the same way that
the contact of the ordinary coil vibrator is.

d. Contact is made and broken mechanically
through a shaft driven by the engine, conse-
quently a spark may be obtained from a bat-
tery that is too weak to operate a vibrator. The
mechanism by which the instantaneous primary
contact is produced is similar to a snap contact
produced by a small sprin<2:-controlled hammer
pulled out of position by a ratchet on the shaft.
The ratchet has as many tcfth as there are cyl-
inders, and runs at the camshaft speed. When
used with a two-cycle enrrine, it runs at the
crankshaft speed if there are four cylinders. If
there are two cylinders, it runs at half the en-

The Automobile Handbook 373

gine speed and the ratchet has four teeth. The
ordinary commutator is not used in connection
with it, but a driving connection must be made
from the crankshaft or camshaft to the vertical
shaft of the spark generator itself, which is
mounted on the back of the dashboard.

The Atwater-Kent system consists of three
parts: 1, The unisparker, which combines the
special form of eontaet-maker, which is the
basic principle of this system, and a high ten-
sion distributor.

Fig. 164
At water Kent Timer Before Moving Lever

2, The coil, which consists of a simple pri-
mary and secondary winding, with condenser —
all imbedded in a special insulating compound.
The coil has no vibrators or other moving parts.

3, The ignition switch.

The operation of the unisparker is shown in
Pigs. 164 to 167. This consists of a notched
shaft, one notch for each cylinder, which ro-

374 The Automobile Handbook

tales at one-half the engine speed, a lifter or
trigger which is pulled forward by the rotation
of the shaft and a spring which pulls the lifter
back to its original position. A hardened steel
latch and a pair of contact points complete the
device.

Fig. 165
Atwater Kent Timer Before Lever Escapes '

The figures show the operation of the con-
tact-maker very clearly. It will be noted that
in Fig. 164 the lifter is being pulled forward
by the notched shaft. When pulled forvsrard as
far as the shaft will carry it, Fig. 165, the
lifter is suddenly pulled back by the recoil of
the lifter spring. In returning it strikes
against the latch, throwing this against the eon-
tact spring and closing the contact for a very
brief instant — far too quickly for the eye to
follow the movement, Fig. 166.

The Automobile Handbook 375

Fig. 167 shows the lifter ready to be pulled
forward by the next notch.

Note that the circuit is closed only during
the instant of the spark. No current can flow
at any other time, even if the switch is left
*'on" when the motor is not running.

By means of the distributor, which forms the
upper part of the unisparker, the high-tension
current from the coil is conveyed by the ro-
tating distributor block, which seats on the end
of the unisparker, to each of the spark plug
terminals in the order of firing.

Pig. 166
Atwater Kent Timer With Contacts Closed

Where the lighting and starting battery is
used for ignition, two wires from the ignition
system should run directly to the battery ter-
minals. They should not be connected in on any
other branch circuit.

376 The Automobile Handbook

The automatic type is cylindrical in Axpi
and consists of a pressed steel casing with a
hard rubber cap, the latter forming the base
of the high-tension distributor. The device is
mounted on a shaft which is driven at half the
speed of the crankshaft. Within the casing is
located the mechanism, consisting of the gov-
ernor which automatically controls the advance,
the circuit breaker and high-tension distribator.

Atwater Kent Timer With Contacts He-opened

At the bottom of the casing is the Tjvemor,
a modification of the centrifugal type which
consists of two pairs of weights, each pair be-
ing pivoted together at their cantors, and two
double arm brackets. When the shaft starts
to revolve, the weights extend away from the
center and the arms change their angular re-
lation in direct proportion to th& speed of the
driving shaft.

The Automobile Handbook 377

In order that the weights will not move away
from the center too easily and give too great
an advance to low speeds, the brackets carry-
ing the springs are so arranged that the weights
have to act against them when obeying the im-
pulse of centrifugal force, and moving away
from the axis of rotation. Virtually each
weight is a bell-crank lever with one point of
connection pivoted to the arm and the other
point of connection pivoted to the weight. The
four weights thus give four bell-crank levers
working in the same direction at the same time
against the four respective springs.

In timing with automatic advance the piston
in No. 1 cylinder should be raised to high
dead center, between compression and power
strokes, then, with the clamp which holds the
unisparker loose, the unisparker should be
slowly and carefully turned backwards, or
counter clockwise (contrary to the direction of
rotation of the timer-shaft), until a click is
heard. This click happens at the exact instant
of the spark. Now clamp the unisparker tight,
being careful not to change its i)osition.

Now remove the distributor cap, which fits
only in one position, and note the position of
the distributor block on the end of the shaft.
The terminal to which it points is connected to
No. 1 cylinder. The other cylinders in their
proper order of order of firing are connected to
the other terminals in turn, keeping in mind the
direction of rotation of the timer shaft.

378 The Automobile Handbook

When timed in this manner the spark oc-
curs exactly, on ** center" when the engine is
turned over slowly. At cranking speeds the
.governor automatically retards the spark for
safe starting, and as the speed increases, the
spark is automatically advanced, thus requir-
ing no attention on the part of the driver.

The first operation in timing the hand ad-
vance unisparker is to crank the engine until
the piston of No. 1 cylinder is on high dead
center between the compression and power
strokes.

The unisparker is then placed on the shaft,
the advance rod from the steering post being
connected to the lug on the side of the uni-
sparker, which is provided for that purpose.

The position of the spark advance lever on
the steering wheel sector should be within "^
inch of full retard, and the connecting levers
should be such as to give the unisparker a
movement of at least 45 degrees to 60 degrees
for the full range of spark advance.

After the spark lever is connected up and the
unisparker is in position it should be left loose
at the driving gear, and, with the motor on
dead center as above directed, the shaft of the
unisparker should then be turned forward or
in the same direction as that in which the timer
shaft normally rotates, until a click is heard,
at which point it should be set by tightening
the driving connection.

Tbp contact points are the only adjustable

The Automobile Handbook 379

feature of the unisparker. These points should
never touch when engine is at rest and the
space between them should vary from 1/100
to 1/64 of an inch, depending upon the strength
of the batteries, spark, heat required, etc. The
spark can be made hotter by decreasing the dis-
tance, and current can be economized by in-
creasing it. Once or twice a season these con-
tacts should be examined and should be kept
flat and bright by means of a small file or
emery cloth on a stick. The proper adjustment
when starting with new batteries is about 1/32
of an inch, if dry cells are used. If storage
battery is used, it may be ijecessary to reduce
this a little. At intervals of six or eight hun-
dred miles of service as the batteries decrease
in strength, these contacts should be closed from
a quarter to a half turn, or until regular fir-
ing is obtained. Do not attempt under any cir-
cumstances to adjust the tension of the springs.

Frequently when high-tension wires are run
from the distributor to the spark plugs through
metal or fibre tubing, trouble is experienced
with missing and back-firing, which is due to
induction between the various wires in the tube.
This trouble is especially likely to happen if
the main secondary wire from the coil to the
center of the distributor runs through this tube
with the spark-plug wires.

"Wherever possible, the distributor wires
should be separated by at least I/2 i^i^h of space
and should be supported by brackets or insu-

380

The Automobile Handbook

lators rather than rtm through a tube. In no
case should the main distributor wire be run
through a conduit with the other wires.

If irregular sparking is noted at all plugs,
examine first the battery and connection there-
from. If the trouble commences suddenly, it

Pie. 168
Connecticut Igniter Head
ie probably diie to a loose connection in the
wiring. If gradually, the batteries may be
wi'iiki'iiing or the contact points may require
altciition. See that the contacts are clean and
bright, and also that the moving parts are not
gummed with oil or rusted.

The Automobile' Handbook 381

l^gnition, Coimectlou.t. The Connecticut an-
tomatic igniter system, Fig. 168, produces a
single spark upon a break occurring in the pri-
mary circuit which, though being closed, has
energized a coil. This break is effected in the
igniter by means of a. cam revolving against a
breaker arm. The high tension spark is dis-
tributed in the same instrument. The igniter
is mounted on a vertical shaft running at half
engine speed irrespective of the number ol

Fig.

Connecticut Breaker Mecbanlem
cylinders. The breaker arm is insulated from
the base. This provides a metallic circuit; or
in other words, no engine ground need be uti-
lized in the primary or battery circuit, as the
primary winding is insulated from the second-
ary ground in the coil. In this case there is
no possibility of the ignition being affected
through grounding or shorts in any other cir-

382

The Automoiile Handbook

cuit of the car, such as disarrangement in lij
ing or starting systems.

The igniter may be taken apart and r
sembled without the aid of any tools. The
tributor ease can be removed by unsnapping
two spring clips on the side, thus exposing
distributor arm carrying the carbon bn
Fig. 169, which can be slipped off the sh

Fig. 170
Connecticut Distributor Rotor

Then remove cotter pin passing through s
and the dust proof cover carrying the uj
})earing can be taken off and the breaker
complete, Fig. 170, can be lifted from the si
As the shaft is not disturbed the timing i
no way affected when the igniter is reassem
on the shaft.

The AutomoiUe Handbook 383

The system is not recommended for use on
dry cells except as an emergency, but is de-
signed to operate from a storage battery
charged by a dynamo.

The automatic switch of the Connecticut
automatic igniter system is a feature that is
individual to this system and unique in igni-
tion apparatus. Its function is to kick oflf the
switch should the primary circuit be closed an
unwarranted length of time, as in the case of a
car being left with the switch on the engine
stopped. This will prevent the draining of
batteries.

Another purpose is to protect the ignition
wiring should a disarrangement occur in the
lighting or starting circuit and an excessive
and destructive amount of current be introduced
into the ignition circuit.

The circuit is closed in the automatic switch
through contacts of the plunger type. These
plungers are held in contact by a slotted lock-
ing plate. This plate is released by the '*off"
button on the switch; or in cases of prolonged
or excessive flow of current, by a vibrating
magnetic release thermostatically effected. The
construction is such that no amount of outside
vibration or jar can in any way affect the lock-
ing plate.

This automatic ''kick off" is accomplished
thermostatically and is a mechanism that has
been employed for many years in telephone
switches.

384 The Automobile Handbook

To time the igniter, turn the engine o^
with petcoeks open, until the piston of the f
cylinder has reached the top of the comp:
sion stroke. Now advance the spark lever
the steering wheel about three-quarters of
way. Remove distributor cap, then set
igniter on driving shaft with set screws lo<
connect advance lever, turn hub of igniter
shaft in direction of rotation until contact poi
are just open, which is the point at which
spark takes place, then tighten the hub
screws. Replace the distributor cap, carefi
noticing which segment of the distributor
brush is opposite, for this is the connectioi
the spark plug of No. 1 cylinder. Com
up the balance of the spark plugs in their
ing order. After connecting all wires you
then ready to try out the ignition. Bei
cranking, fully retard your spark lever.
suit individual requirements, it may be ne
sary to slightly advance the igniter hub
greater speed is required, or slightly retar(
for very slow speed.

This igniter is completely housed and j
t(icted. Little care is required to keep it
working condition. About every four or
thousand miles the distributor cap should
removed and wiped out. On the ball-beai
igniter, the distributor arm should be w
drawn and one or two drops and no men
good oil injected into the hole in the end
the shaft which carries the distributor c

The Automobile Handbook 385

This will lubricate the lower ball-bearing. No
other parts need oiling. Care should be taken
to see that oil does not reach the contact points.
On the plain bearings or self-lubricating type,
the bearings require no attention whatever.

The contact points will probably require no
attention until run at least ten thousand miles
and in some cases they may operate for over
thirty thousand miles without attention.

The points do not require refiling or clean-
ing even though they may be very rough and
irregular, but when they become so badly
burned as to cause missing they should then be
renewed, in which case proceed as follows:

Remove the distributor cap and arm, discon-
nect advance lever and wires, remove cotter pin
in igniter shaft, then spring washer and fibre
washer, and lift the housing from its shaft.

The contact adjustment screw will be noticed
under the dust ring, it being locked from turn-
ing by a hexagon nut on the screw inside near
the end. Care should be taken to see that this
nut is tightened up snugly after making a re-
placement or adjustment. When it is necessary
to adjust these points they should be set so
that when the roller rests on the point of the
cam, they open about the same as a magneto
interrupter. It is not necessary, however, to
make this adjustment as accurately as on a
magneto. The adjustable contact screw can
be removed by taking oflf the lock-nut and then
screwing it back out of the housing.

386 The Automoiile Handbook

The contact on the breaker arm is riveted
into it and a complete new arm is necessary in
making a replacement.

This arm can be readily removed by taking
out the small cotter pin in the end of the stud
on which it moves, remove small fibre washers
and the arm can then be lifted out.

When replacing the arm on the stud before
putting the cotter pin in place, be sure and re-
place the little fibre washers which rest on the
top of the arm just under the little cotter pin
and the fibre washer on the stud in the bottom
of the cup.

Ignition, Delco. The Delco system of bat-
tery ignition makes use of a combined breaker
and distributor usually mounted on, and driven
from, the lighting dynamo or motor-djrnamo.
In some installations the ignition unit is placed
by itself, but the construction and operation is
the same in either case.

The distributor and timer are driven through
a set of spiral gears attached to the armature
shaft or its extension. The distributor con-
sists of a cap or head of insulating material,
carrying one high-tension contact in the center,
with similar contacts spaced equi-distant about
the center, and a rotor which maintains con-
stant communication with the central contact.

The rotor carries a contact button which
sends the secondary circuit to the spark ping
in the proper cylinder.

The Automobile Handbook 387

Beneath the distributor head and rotor is the
ler, Pig. 171, which is provided with a acrew
the center of the shaft, the loosening of which

Fig. 171
Ico Ignttion Head Breaker. A, Cam Holding
Screw. B, Battery Current Coo tacts. C,
Breaker Cam. D, Resistance Wire Spool. B,
Cam Contact Levers. M, Dynamo Current Con-
tacts.

0W8 the cam to be turned in either direction
secure the proper timing, turning in a clock-
ae direction to advance and counter-clock-
ae to retard.

388 The Automobile Handbook

The spark occurs at the instant the timer
contacts are opened.

The adjustment screw must always be set
down tight after the cam is adjusted.

The same weight which operates tho arm on
the regulating resistance also operates the auto-
matic spark control. In addition to the auto-
matic spark control, a manual spark control
is provided, which is operated by the lever on
the steering column, and is connected to the
lever at the bottom of the motor generator.
The manual spark control is for the purpose of
securing the proper ignition control for vari-
able conditions, such as starting, differences in
gasoline and weather conditions. The auto-
matic control is for the purpose of securing the
proper ignition control necessary for the varia-
tions due to speed alone.

The resistance unit is a coil of resistance wire
wound on a porcelain spool. Under ordinary
conditions it remains cool and offers little re.
sistance to the passage of current. If for any
reason the ignition circuit remains closed for any
considerable length of time, the current passing
through the coil heats the resistance wire, in-
creasing its resistance to a point where very lit-
tle current passes, and insuring against a waste
of current from battery and damage to the igni-
tion coil and timer contacts. When the arm
that cuts the regulating resistance into the
shunt field circuit is at the top position (that
is, at high speeds), the resistance unit is cut

The Automobile Handbook 389

out of the ignition circuit. This increases the
intensity of the spark at high speeds.

To time ignition: Fully retard the spark
lever. Turn the engine so that upper dead
center on flywheel is about one inch past dead
center with No. 1 cylinder on the firing stroke.
Loosen screw in center of timing mechanism
and locate the proper lobe of the cam by turn-
ing until the button on the rotor comes under
the high tension terminal for No. 1 cylinder.
Set this lobe of the cam so that when the back
lash in the distributor gears is rocked forward
the timing contacts will be open, and when the
back lash is rocked backward the contacts
will just close. Tighten screw and replace rotor
and distributor head.

If the motor fires properly on the ''M'' but-
ton, but not on the **B*' button, the trouble
must be in the wiring between the dry cells or
the wires leading from the dry cells to the com-
bination switch, or depleted dry cells.

If the ignition works on the **B'' button and
not on the **M" button, the trouble must be
in the leads running from the storage battery
to the motor-generator, or the lead running
from the rear terminal on the generator to the
combination switch, or in the storage battery
itself, or its connection to the frame of the car.

If both systems of ignition fail and the sup-
ply of current from both the storage battery
and dry cells is ample, the trouble must be in
the coil, resistance unit, timer contacts or con-

390 The Automoiile Handbook

denser. This is apparent from the fact that
these work in the same capacity for each sys-
tem of ignition.

The following directions for upkeep apply in
a general way to the **M'' or **Mag'' igni-
tion on all of the Delco systems, but dp not
apply to the dry battery ignition.

The contact points are of tungsten metal,
which is very hard and requires a very high tem-
perature to melt. These should be kept clean and
smooth on the faces. This can be done by hold-
ing in a vice and using fine emery cloth held
underneath a flat file. They should be so ad-
justed that when they are open they are apart
ten-thousands of an inch and the contact arm
should move about fifteen-thousands of an
inch after the contacts close.

The most common causes of contact trouble
are due to the following: (1) Resistance
unit shorted out, resulting in excessive current
through the contacts, especially at low speeds.
(2) Abnormally high voltages due to run-
ning without the battery or with a loose con-
nection in the battery circuit. (3) A broken
down condenser.

T\w distributor head should be properly lo-
('at(Ml, that is with the locating tongue of the
li()l(l-(lown clip in the notch on the distributor
lioad. Tlie lioad should be kept wiped clean
fi'oiii dust and dirt and in some cases it is
advisable to lubricate this head with a small
amount of vaseline.

The Automobile Bandhooh

391

The rotor should be kept free from dust and
dirt and the rotor button polished bright. The
rotor button should be fully depressed' before
putting on the distributor head to make mire

the spring will allow the button to go down to
the proper level and not subject it to undue
pressure on the distributor head.

392 The Automobile Handbook

Remy Battery System. This make of igni-
tion equipment is furnished in two principal
types, one of which might be called *' magneto
type" and the other one a ** vertical ignition
head.''

The magneto type equipment, Fig. 172, bears
a very close resemblance to the breaker and dis-
tributor end of a separate unit magneto, being
composed of a distributor having terminals for
the spark phig leads and below the distributor
a breaker exactly similar in construction to that
with magnetos. In connection with this unit
a two-way switch is used, giving either dry bat-
tery or generator as a source of ignition current.
To transform the current to one of high-ten-
sion a separate coil is used.

This coil differs from ordinary coil construc-
tion inasmuch as both ends of the primary wind-
ing are insulated, so that, in the event of a
ground occurring in the lighting or starting cir-
cuits, the ignition will be unaffected. The coil
is provided with a safety gap as a further
means of protection.

The coil is wound for six volts and is to be
used in connection with a storage battery or
with five dry cells. The coil is to be mounted
on the crankcase within 6 or 8 inches of the
breaker points as the condenser is incorporated
in the coil and not on the generator. A special
top plate is provided to securely hold coil in
position.

The circuit breaker platinum points may be

The Automobile Handbook

393

inspected by removing the Bakelite housing
cover. The points should have a, smooth, clean,
fiat surface at all times. The break, or gap, of
these points should be from 15 to 20 thou-
sandths of an inch. The circuit breaker may,
if desired, be removed without the aid of tools.
The high-tension current is distributed to the
spark plug cables by means of a hard carbon '
brush making contact with distributor segments.
Neither distributor nor brush will require any
attention whatsoever.

Ftg. 173
Hemy Vertical Ignltloi

An oiler is provided for the distributor shaft,
— only a few drops of light oil every one thou-
sand miles will suffice.

The use of spark plugs which permit of the
points being adjusted to a definite gap is recom-
mended. The gap between the points should be
from 20 to 25 thousandths of an inch.

394 The Automobile Handbook

If the motor misses when running idle or
pulling light, the plug gaps should be wider.
If motor misses at high speed or when pulling
heavy at low speed, the plug gaps should be
made closer.

The vertical ignition head consists of a com-
bined breaker and distributor mounted in one
case, Fig. 173, and adapted to be driven from a
vertical shaft usually on or near the lighting
dynamo.

Some of these distributors have a manual ad-
vance for the spark, while some are built with
a mechanism which automatically advances the
spark to meet the requirements of the engine
upon which it is installed.

The high-tension current is distributed to the
spark plug leads by a segment which revolves
close to, but does not touch, the pins in the dis-
tributor head.

Either iridium-platinum, tungsten or silver is
used in the contact points, the choice depending
upon which is best suited to the installation.

The coil furnished with this system has a spe-
cial ventilating base which may be bolted se-
curely to the engine frame. Its current con-
sumption is limited by a resistance located on
top of the coil and which is in series with the
primary winding.

The metal base of the coil makes an electrical
connection with the engine or car frame for one
side of the secondary winding. Therefore, it is
very important before mounting the coil to see

The Automobile Handbook 395

that all foreign matter, such as dirt, grease,
paint, etc., is removed from the place where the
coil is to be mounted. It is also very important
that the base of the coil be fastened down se-
curely at all times.

The switches furnished with this equipment
are arranged to reverse the direction of current
flow through the circuit breaker each time the
ignition is used.

It is absolutely necessary that the ignition
switch be placed in the V*off" position when the
engine is not running. If it is left in the **on"
position, current from the storage battery will
be dissipated in the ignition coil which, if con-
tinued, will exhaust the battery.

By an insulated system is meant one in which
the circuit breaker is not grounded. By glanc-
ing at the wiring diagram it will be seen that
the circuit from the switch around through the
breaker box and back to the switch again is not
grounded, and that the switch reverses the di-
rection of the current flow through this circuit
at each quarter turn.

If the insulation is worn off any one of the
wires and the copper touches any of the metal
parts of the car, a short circuit will result which
will either render the system inoperative by
burning out a fuse or will discharge the bat-
tery. A periodical inspection should be made of
all wiring to see that it is not rubbing or chafing
on any of the metal parts of the car and that all
connections are tight and secure.

396 The Automobile Handbook

The contact screw should be adjusted with
the wrench furnished with the system, so that
the maximum opening of the points is .020 to
.025 inch, or the thickness of the piece riveted
upon the side of the wrench. The rebound
spring should be at least .020 of an inch from
tlie breaker arm when the points are at their
maximum opening.

To obtain the best results the spark-plug gaps
should be adjusted to .025 of an inch.

Ignition, Westinghouse. Dual ignition is
obtained in the Westinghouse system; that is,
the ])attery is an independent source of supply,
as well as the generator operating with the bat-
tery, while the interrupter, ignition coil and
distributer are common to both.

The interrupter is so constructed that the
period of contact is practically the same at any
speed. The spark voltage, therefore, does not
fall off at higli speeds, but is practically the
same at all speeds.

Automatic spark advance is a feature of the
Wc'stingliouse generator. The automatic ai*
ynnci' works over a range of 45°. Provision is
made for manual operation also, and it is recom-
m('ii(l(Hl that this hi* connected up, but the spark
h'Vf'r need not ordinarily be touched after the
original adjustment, the automatic device taking
faro of all adjustments in running.

Tlie interrupter is mounted on the generator
shaft and contacts are operated by a centrifngal
device that automaticallv adiusts the spark ad-

The Automobile Handbook

397

vanee to the speed, keeps the period of contact
nearly constant at all speeds and prevents any
inequality between the two interruptions that
occur in succession during each revolution.

Fis- 174
Weatlngbouse Ignition and Lighting Dynamo

The ignition outfit consists, in addition to the
lighting system and storage battery, of a dis-
tributer and an interrupter, which are made a
part of the generator. Fig. 174, and an ignition
coil and switch. The ignition coil transforms
the six volts of the battery up to the high ten-
sion required for the spark plugs. The inter-
rupter closes and then opens the ignition cir-
cuit at each half revolution of the generator
shaft, and the distributer directs the high-ten-
sion current to each of the spark plugs in suc-
cession.

398 The Automobile Handbook

The operation of the ignition system, indad-
in^ the intermpter and distributer, ignition coil
and switch, begins with the "making" of the ■
primary circuit of the coil when the centrifugal
weights push down the fibre bumper, allowing
the interrupter contacts to close. Fig. 175. Then
the weight moves off the fibre bumper, allowing
the contacts to suddenly separate or open, when
a high voltage is induced in the secondary oE
the ignition coil and directed by the distributer

Pig. 175
Weatlnghouse Ignition Breaker, Low Speed Po-

Bition
to the proper spark plug, causing a spark. Aa
the speed of the engine increases, the weights
are thrown out from the center and automatic-
ally advance the time of closing or openii^ the
interrupter contacts, and hence advance the
spark, Fig. 176. At the same time, due to their
sbapc, they keep the contacts closed during a
greater part of the revolution when running at
high speed; this makes the period of contact

The Automobile Handbook 399

practically the same at all speeds and prevents
the spark voltage from falling off at high
speeds.

To connect the ignition system to the circuit,
insert the ping into the ignition switch and
move the switch handle to the "on" portion.

Fig. 17 S
WestlnghouBe Ignition Breaker, High Speed Po-

In inserting the ignition plug pay no attention
to the position of the brass contact pieces on
the plug. It is desirable that the contacts will
average up as often in one as in the other of the
two possible positions, as this reverses the direc-
tion of the current through the interrupter con-
tacts and greatly increases their life.

The spark plug should be set with slightly less
than 1/32 inch between tips for best operation.
Oily or carbonized plugs will often cause miss-
ing, and if dirty, they should be well brushed
i^c|e and outside with gasoline and wiped per-

400 The Automobile Handbook

fectly dry. A crack in the insulating material
will, of course, probably lead to failure of spark
in the cylinder.

The interrupter stop is adjusted so as to give
the proper pressure on the bumper. When the
engine is not running and the weights are in a
closed position, there should be a space of 3/64
inch between the bunmer lever and the stop.
After the stop is adjusted, the contact screw
should be adjusted by means of a wrench, so
that with the cam lever against the upper stop,
the contacts are open .005 inch. After setting
for this separation, tighten the clamping screw
so that the contact screw is held firmly. Be sure
that the contacts open up positively and that
the moving element moves clear up against the
upper stop when released, with some spring ten-
sion still remaining to hold it in this position.
See that the contacts are kept free from all oil
and grit.

Interrupter weights should turn freely on
their supporting pins and should also clear the
centrifugal weight spring support by approxi-
mately .01 inch. They should show no lost mo-
tion between the two interlocking weights. In
making any readjustments, be careful that when
the engine is turned over very slowly by hand,
both weights depress the moving part of the
interrupter enough to definitely close the con-
tacts, otherwise there will be a tendency to miss
fire in every second cylinder, especially at low
speeds and if the contacts are worn more or less.

The Automobile Handbook 401

When the weights are in the inner position,
the springs should just touch the fibre-covered
pins on the weights without exerting any appre-
ciable pressure over that required to just posi-
tively return the weights to the innermost posi-
tion. If necessary to adjust these springs, al-
ways bend the supporting arms and not the
springs themselves.

Distributer brushes should slide freely in
their holders and the springs should push them
out so as to extend from the holder about %
inch when the distributer plate is removed from
the generator. These brushes should, however,
be retained firmly by their springs so as to never
tend to fall completely out of the tubes. Be
sure that both these brushes are in place in the
distributer.

Distributer plate should be kept clean and
free from carbon dust between brushes and con-
tact surfaces by an occasional wiping. Any
pitting of the distributer which is in advance
of the contacts, indicates that the distributer
gear is set one tooth or so too far back against
the direction of its rotation. This may cause
intermittent firing of the cylinders at the higher
speeds, with consequent loss of power. The
gear is set correctly at the factory, and if this
setting is not disturbed the above trouble will
not be encountered.

The distributer gear is meshed with the pinion
on the generator shaft so that the mark at the
edge of the gear lines up with the tooth of the

402

The Automobile Handbook

pinion that is slightly beveled. In coupling the
generator to the engine, place the piston of
cylinder No. 1 on dead center at the end of the
compression stroke. Remove the distributer
plate and turn the generator back so that the
line of the distributer brushholder block corre-
sponds with the line on the end bracket. Couple
the engine and generator shafts while in this
position.

nilionlermindla

istributor Plate

ntarupierCb

Swiicb , M

Tenninal »|a

lnl«miplirC9dbicl»

Fig. 177
Westinghouse Vertical Ignition Head

The Westinghouse vertical ignition unit can
be used for ignition from storage batteries or
phiin lighting generators, Fig. 177. This set

The Automobile Handbook

403

contains interrupter, spark coil and condenser,
and distributer, all in one unit. One wire from
the battery or generator to the ignition unit and
one wire to each spark plug are all that are
required.

lit To 'Spark Piugs

'Oistributit Brushes

^iwMWMwwJ^ .Induction Coil

Interrupter

f^^

□

To Ignition Unit
Xondenm w//^;, ^y^nch

Ignition
witch

fuse Box

Battery

From Battery

Fig. 178
Westinghouse Vertical Ignition Wiring

The interrupter, located at the lower end of
the set, has the same type of circuit-breaker as
that on the Westinghouse ignition and lighting

404 The Automobile Handbook

generators, but no automatic spark advance fea-
ture. It can be used equally efficiently for either
direction of rotation without charge. The in-
terrupter is enclosed by a spring collar which
can be readily removed for inspection or adjus^
raent of the contacts. The Collar makes a tight
joint and is clamped by a screw which prevents
it from slipping. See wiring diagram, Fig. 178.

The Westinghouse Ford vertical ignition unit
is made up of four essential parts, namely, the
interrupter, the condenser, the induction coil,
and the distributer, all included in one case.

The operation of the interrupter can be ob-
served by loosening the thumbscrew and sliding
upward the loose section of the insulation case,
which forms the interrupter cover.

With the ignition switch turned to the ''on**
position and the engine turning over, each seg-
ment of the interrupter cam in turn passes on
and off the fibre bumper. As each cam passes
off the bumper, the interrupter contacts close,
closing the circuit from the battery to the pri-
mary winding of the induction coil. Then as
they pass on the bumper, the contacts are
opened, suddenly opening the circuit, thus in-
ducing a high voltage in the secondary of the in-
duction coil. This voltage is directed by the
distributer on the top of the ignition unit to
the proper spark plug, causing a spark at the
spark gap of the plug inside the cylinder, and
igniting the charge therein.

The contact screw should be adjusted with a

The Automobile Handbook 405

screwdriver so that, with the cam against the
bumper, the contacts are open .008 inch.

If the contacts show pitted or irregular sur-
faces they should be smoothed up with a very
fine file, making certain that the surfaces come to-
gether squarely after adjustment has been made.

Ignition, Magneto Type. Magneto ignition
makes use of a separately mounted machine
having its own armature and field magnets (per-
manent magnets) and being driven from the
engine. A magneto always consists of a rotat-
ing member, this being a shuttle wound arma-
ture in most cases, or simply pieces of iron in
the inductor type. This rotating member,
through the change in the path of the lines of
force from the magnets, produces a current in
a coil separate or on the armature in the
shuttle wound form, or mounted separately in
the inductor magneto. This current rises from
zero to its maximum voltage twice for each
revolution of the magneto shaft, one impulse
flowing in one direction through the windings
and the next one (on the other half revolution)
flowing in the opposite direction. The current
from a magneto always reverses its direction in
this way and is, therefore, an alternating cur-
rent. The current from a lighting dynamo does
not reverse its direction and is a direct current.
For this reason no magneto can ever be used for
charging a storage battery, a battery requiring
current that always flows in one direction
through the circuit.

406 The Automobile Handbook

Combined with the armature and the perma-
nent steel magnets that provide the field for
the magneto is a breaker mechanism that inter-
rupts the flow of current through the circuit
whenever a spark is desired; and also a dis-
tributor that carries the contacts for delivering
the high-tension current through the wires that
lead to the spark plug in the cylinder that is
ready to fire. While the details of construction
of magnetos differ as described in the following
pages, all types contain the parts described
above. A shuttle wound armature with a break-
er mounted on its shaft is shown in Fig. 179.

Fig. 179

Shuttle Type Magneto Armature With Breaker
The breaker may take any one of several
forms, a commonly used construction being
Kliown in Fig. 180. The circuit is completed
through the contacts A, one of which is solidly
numnted, and the other one attached to the mov-
abl(? arm B. The arm carries a fibre block that
strikes a stationary cam when it is revolved on
tlic armafurc shaft, and inasmuch as the arm i»
pivoted, the contacts are separated to interrupt
the circuit and cause a spark to come from
tiif winding of the high tension coil of the sy-

The Automobile Handbook

407

tem. The fine winding that forms the high ten-
sion coil may be wound around outside of the
armature windjng on the shuttle type, or may
be mounted in a housing separate from the
magneto. With the high tension coil on the
armature, the magneto is self-contained and pro-
duces a spark without outside parts, being called
a true high tension magneto. Those magnetos
using outside coils generate the current in their

Fig. 180
Magneto Breaker

armature and send it through the heavy wind-
ing of the separate induction coil, or trans-
former coil. This separate coil has also a fine
wire winding in which the high tension spark
plug current is induced by the breaking of the
circuit through the heavy wire when the break-
er on the magneto opens.

The system known as "single ignition," when
using a magneto, comprises a true hi

408 The Automobile Handbook

machine from which wires lead to the spark
plugs. The only other wire required is one to
the switch that will allow the driver to stop the
production of sparks by connecting the arma-
ture winding to the frame of the car, or ground-
ing it. No other source of current is provided
with single ignition.

** Double ignition'* provides a true high-ten-
sion magneto, as described, and in addition, a
complete, and entirely separate, battery, timer
and coil system with a separate set of spark
plugs and wiring.

**Dual ignition*' uses a magneto similar to
the single ignition high-tension type, but pro-
vides an additional breaker and induction coil
through which current may be led from a set
of dry cells or a storage battery, thus providing
a source of current other than that of the
magneto armature when desired for starting or
emergency use.

** Transformer coil ignition" makes use of a
magneto that produces in its armature, or by
inductor action, a current of low voltage that
is led to a separately mounted transformer, or
induction coil. The coil is connected by wires
to the breaker and distributor on the magneto.

How TO Remove and Replace a Magneto.
When about to replace or remove a magneto it
is well to see that all separable parts are prop-
erly marked, and if not, mark them. This may
])e done with a ec^nter punch, cold chisel, letters
or numerals. In Fig. 181 is shown the guide

The Automobile Handbook

409

ks generally used in connection with a high-
iion magneto of a four-cylinder motor. The
:er punch marks C, on the Oldham coupling
1 as is usually employed on the magneto
:t between the magneto and its driving gear,
e as a guide in replacing the magneto. All
; is necessary in replacing a high-tension
jneto so marked on a four-cylinder, four-
e motor is to see that the marks are directly
osite each other; but in two or six-cylinder
ors, where the crankshaft and the armature
he magneto do not run at the same speed,
) must be taken either not to move the
ikshaft while the magneto is off or to check
the timing before it is replaced. In the
e illustration is shown the method of mark-

Fig. 181

the timing gears. These marks are made
1 a cold chisel and are generally present in
to-date construction.

410 The Automobile Handbook

Figs. 182 and 183
Bosth Hij-'h Tension Magneto, Type "DU". !.
Annatiiro End I'late for Primary Wlndtng Con-
noi'iion. 2, Hreiiker Fastening Screw. 3.
nrpiikcr Contact Hlock. 4, Breaker Disc, S.
iMXtt- Pliitlniiin Contact Screw. 6, Short Platt-
niiiii foiilact Sctpw. 7, Flat Spring for Breakrr
l.cvcr. 8, Hrnaker I.ever. 9, Condenser, li>.
Colletlor Ring for High Tension Current. II.
lEi«li TenKiou Carbon Bruali. 12, Carbon Brush
Holder, i:!, Condiirlor Itar Terminal. 14, Con-
ductor Bar. 13, TliBlributor Brush Holder. 16.
niBiriliuiiir Ciirbnii lirusli. 17, Distributor Plate.
IS. Cfdtra] Coiiriict on Distributor. 19, Brass
KfKitifnt. I'll, Terminal for Spark Plug Wire.
L'1. Sicid Breaker Cam. 22, Dust Cover. 24,
tlrouiirliiif.' Terminal. 25. Distributor Block
lloliliiis S|>riiiK. 116. Uronker Timing Lever.
1 17. lireaker Cov(-r. IIR. Conducting Spring for
fli.jujulirii.- Tcrminul. 119, Breaker Cover Hold-
irif. Hi.riny:.

The Aulomobile Handbook

411

Bosch Magnetos. The Bosch high tension
magneto. Pig. 182, generates its own high-ten-
sion current directly in ihe armature winding
and without the use of a separate coil or other
apparatus. Apart from the cables connecting
the magneto to the plugs, the Bosch high-ten-
sion magneto requires no external connections.

Fig. 183

The armature carries two windings. The pri-
mary consists of a few layers of heavy wire and
the secondary of a great number of layers of
fine wire. One end of the primary winding ia
grounded on the armature core, and the live end
is brought out to a circuit-breaking device. The
grounded end of the secondary winding is con-

412 The Automobile Handbook

nected to the live end of the primary winding
so that one is a continuation of the other.

During certain portions of the rotation of the
armature the primary circuit is closed, and the
variations in magnetic flux have their effect in
inducing an electric current in it. When the
current reaches a maximum, which will occur
twice during each rotation of the armature, the
primary circuit is broken, and the resulting ar-
mature reactions produce a high-tension current
of extreme intensity in the secondary winding.
This current is transmitted to a distributer by
means of which it passes to the spark plug of
the cylinder that is in the firing position.

The magneto interrupter. Fig. 183, is fitted
into the end of the armature shaft which is
taper-bored and provided with a key-way. The
interrupter is held in position by a fastening
screw, and may easily be removed. In replacing
it, care should be taken that the key fits into
the key-way and that the fastening screw is
well tightened.

Twice during each revolution of the armature
the primary circuit closes and opens, this being
effected by the interrupter lever coming in con-
tact with a steel segment, which is supported
on the interrupter housing. When the magneto
interrupter lever is not being acted upon by the
steel segment, the platinum points are in con-
tact, thus closing the primary circuit. Then
as the armature rotates farther and the inter-
rupter lever again comes in contact with a seg-

The Automobile Handbook

413

ment, the platinum points (interrupter eon-
tacts) open and thus interrupt the primary eir-
cuit. At the opening of the contact the ignition
spark occurs instantaneously.

The distance between the platinum points
when the magneto interrupter lever is fully de-
pressed by one of the steel segments must not
exceed 1/32 inch. This distance may be adjusted
by means of a long platinum screw, and should
be in accordance with the steel gauge that is
pivoted to the adjusting wrench.

Magneto
Interrupter

Fig. 184
High and Low Tension Circuits of Bosch Magneto

The connections of the magneto, Fig. 184,
consist of a high-tension cable from the dis-
tributor to each spark plug, and a low-tension
cable leading to the switch.

In order to protect the insulation of the arma-
ture and of the current-carrying parts of the

414 The Automobile Handbook

apparatus against excessive voltage, a safety
spark gap is arranged on the dust CQver. It
consists of a short pointed brass rod set on the
dust cover, and a second pointed brass part sup-
ported a short distance from it in the center of
the stealite cover of the housing. The insulated
point is connected into the secondary circuit,
and should there be any interference with the
circuit normally provided through the spark
plug the safety spark gap provides a i)oint of
discharge.

If a spark is observed passing in the safety
spark gap it is an indication that there is an
interruption in the regular secondary circuit,
and the cause should be at once investigated.

A simple test for the magneto is to disconnect
the grounding cable from grounding terminal
and also to disconnect the spark plug cables.
The motor should then be cranked briskly, and
the safety spark gap closely observed. If sparks
are seen at this point, it is an absolute indica-
tion that the magneto is in proper ox>erating
condition. If no sparks are observed it will be
necessary to make sure that the primary cir-
cuit is properly interrupted by the magneto in-
terrupter. Holding spring must be moved side-
ways, interrupter housing cover taken off, and
it must be ascertained whether fastening screw
is well tightened. After this it should be ob-
served whether the platinum points are in con-
tact when the steel cams are not acting on the
magneto interrupter lever, also whether tbey

The Automobile Handbook 415

paxate the correct distance, l/25th inch, when
e interrupter lever is resting on one of the
eel cams. Otherwise the distance must be
Ijusted by means of the platinum screw. The
atinum contacts must be examined and any
1 and dirt removed; in case the contacts are
leven (but only then) they must be smoothed
ith a fine flat file. If, after continued use, the
atinum contacts are completely worn down,
e two platinum screws must be renewed.
The Bosch dual magneto is of the standard
osch type, and produces its own sparking cur-
nt, which is timed by the revolving inter-
ipter. The parts of this interrupter are car-
ed on a disk that is attached to the armature
id revolves with it, the segments that serve
I cams being supported on the interrupter
msing.

In addition, the magneto is provided with a
eel cam having two projections, which is built
to the interrupter disk. This cam acts on a
ver that is supported on the interrupter hous-
Lg, the lever being so connected in the battery
rcuit that it serves as a timer to control the
3W of battery current through the coil.
It is obvious that the sparking current from
le battery and from the magneto cannot be led
► the spark plugs at the same time, and a fur-
ler change from the magneto of the indepen-
3nt form is found in the removal of the con-
acting bar between the collecting ring and the
istributer. The collecting ring brush is con-

416 The Automobile Handbook

nected to the switch and a second wire leads
from the switch to the terminal that is centrally
located on the distributer.

When running on the magneto the sparking
current that is induced thus flows to the dis-
tributer by way of switch contact. When run-
ning on the battery the primary circuit of the
magneto is grounded, and there is, therefore,
no production of sparking current by the mag-
neto; it is then the sparking current from the
coil that flows to the distributer connection. It
will thus be seen that of the magneto and bat-
tery circuits the only parts used in common are
the distributer and the spark plugs.

The end plate of the coil housing carries a
handle by which the switch may be operated.
By means of this switch either the magneto or
the battery may be employed as the source of
ignition current, and in its operation the entire
coil is rotated within the housing. The inner
side of the stationary switch plate is provided
with spring contacts that register with contact
plates attached to the base of the coil.

For the purpose of starting on the spark, a
vibrator may be cut into the coil circuit bv
pressing the button that is seen in the center of
the end plate. Normally, this vibrator is out
of circuit, but the pressing of the button brings
together its platinum contacts and a vibrator
spark of high frequency is produced. It will
be found that the distributer on the magneto is
then in such a position that this vibrator spark

The Automobile Handbook

417

is produced at the spark plug of the cylinder
that is performing the power stroke ; if mixture
is present in this cylinder ignition will result
and the engine will start.

Pig. 185
Bo9ch Dual System Wiring Diagram

The dual system requires four connections be-
tween the magneto and the switch. Fig. 185;
two of these are high tension and consist of wire
No. 3 by which the high-tension current from
the magneto is led to the switch contact, and
wire No. 4 by which the high-tension current
from either magneto or coil goes to the distribu-
tor. "Wire No. 1 is low tension, and conducts
the battery current from the primary winding
of the coil to the battery interrupter. Low-ten-
sion wire No. 2 is the grounding wire by which
the primary circuit of the magneto is grounded

418

The Automobile Handbook

when the switch is thrown to the "off" or to
the battery position. Wire No. 5 leads from the
negative terminal of the battery to the coil, and
the positive terminal of the battery is grounded
by wire No. 7 ; a second ground wire No. 6 is
connected to the coil terminal.

rig. 186

Method of Setting Armature of Boech Magneto

The timing of the Bosch Dual Magneto is
identical with the standard type. The dual
maf^neto is so arranged that the battery inter-
riipter breaks its circuit approximately 10 de-
grees later than the magneto interrupter.; this
feature gives the full timing range of the mag-
neto. "With the timing lever fuHy retarded and
fhc switch on the battery position, the battery
spark will occur after the piston has passed

The Automobile Handbook 419 ♦

dead center and is moving on the power stroke.
The possibility of a back kick is thus eliminated.
The magneto should be placed in position on
the bed plate or pad provided for it, the bolts
or straps being properly secured; the driving
gear or coupling, however, should be loose on
the armature shaft. The dust cover, which is
an aluminum plate located under the arch of
the magneto, should then be removed, and this
is accomplished according to the design of the
various types of magnetos.

The engine should now be cranked until one
of the pistons, preferably that of cylinder No. 1,
is at the top of the compression stroke. With
the engine in this position, the armature should
be rotated by hand in the direction in which it
will be driven until it is approximately in the
position illustrated in Fig. 186. The setting of
the armature is determined by the dimension
marked B, Fig. 186, as follows:

''DU3'' ModeU. 11 to 14 mm.

''DU4'' Model 4 13 to 15 mm.

*'DU6''Model4 16 to 20 mm.

'*DU3''Model4 Stbllmm.

''DU4'' Model 4 10 to 13 mm.

''DU6'' Model 4 12 to 16 mm.

With the armature held in the proper posi-
tion, the gear or coupling should be secured.
The greatest care should be exercised to prevent
the slipping of the armature during this opera-
tion.

In the fully enclosed magneto it is unneces-

420 The Automobile Handbook

sary to remove either the interrupter housing
cover or the distributer plate in order to deter-
mine the setting of the instrument, or to locate
the distributer terminal with which contact is
made.

The magneto having been bolted into posi-
tion, the crankshaft is to be turned to bring
one of the pistons, preferably that of cylinder
No. 1, to the firing position for full advance.

The armature is then rotated until the figure
**V^ can be seen through the window in the
face of the distributer plate. The cover of the
oilwell on the distributer end of the magneto
is then to be raised, and the armature is to be
turned a few degrees in one direction or the
other until the red mark on one of the dis-
tributer gear teeth is brought to register with
the red marks on the side of the window located
between the two oil ducts.

The magneto is then in time for the full ad-
vance position, and the gear or coupling is to be
secured to the armature shaft. Great care
should l)e taken not to disturb the position
eith(T of the crankshaft or the armature shaft
when fitting the driving member.

Boscir Enclosed Types. In the **DTJ*' dual
ma^iK^to, the current is led from the collector
ring eonnoetion to the coil and back to the
distri])utor terminal that is located in the cen-
ter of the distributer plate. In the enclosed
dual magneto, this central terminal is elimi-
nated, and the current is led internally to "the

The Automobile Handbook 421

distributer from a connection on the shaft end
3f the magneto. To expose this terminal, the
shaft end bonnet should be removed, which is
done by withdrawing the two screws in its lower
flange, and sliding the bonnet backward. The
terminal will then be seen to be a vulcanite post*
with a boss that projects through a hole in the
bonnet. In the top of this post are two vertical
[loles, in the bottom of each of which is a screw.
These screws are to be withdrawn. The ends
)f the high-tension wires No. 3 and No. 4 lead-
ing to the coil are then to be cut off square,
ind after being led through the hole in the bon-
let, are to be pressed to the bottoms of the
planting holes in the boss. The pointed screws
ire then to be replaced in the vertical holes, and
n being driven home they will pierce the cables
[and their insulation) and make the required
jonnections. It is essential to use a screwdriver
)f the proper size, for a tool with too large a
)lade will inevitably crack the vulcanite. Great
jare must be taken to apply the screwdriver to
;he screws vertically in order to avoid cracking
he vulcanite by side pressure. When the con-
lections are made the bonnet is to be replaced.
Bosch Upkeep and Care. It will be noted
hat the press button on the coil is arranged to
let in either of two positions, which are indi-
cated by an arrow engraved on its surface, or
)rojecting from its edge. When this button is
n such a position that the arrow is pointing on
;he word ''run'' a single contact spark will be

422 The Automobile Handbook

produced when the engine is cranked, or wheii
the engine is running with the switch in the
battery position. Under all ordinary conditions
the button position should invariably be used.

When the engine is chilled, however, or under
poor mixture conditions, starting can frequently
be facilitated by pressing down the button and
turning it slightly to the right so that .the arrow
is pointing to the word ** start." This will lock
the vibrator in circuit, and a shower of vibrator
sparks will be produced in place of the single
contact spark.

The platinum points of the magneto inter-
rupter should be kept clean and smooth and so
adjusted that they are open about 1/64 inch,
or the thickness of the gauge attached to the ad-
justing wrench, when the magneto interrupter
lever is wide open on one of the rollers or seg-
ments. It should not be necessary to clean or
readjust these points oftener than once a season,
and it is not advisable to readjust them until
their condition and the missing of the engine
show it to be absolutely necessary.

Each coil is stamped with the voltage of the
battery current for which it is wound, and if
this voltage is not exceeded the platinum con-
tacts of the battery interrupter will not require
attention for long periods. When this battery
int(Trupter lever is being operated by the roll-
ers or segments, the platinum points should be
slij^litly wider open than the contact points of
the magneto interrupter — the proper distance
being al)out 1/50 inch.

The Automobile Handbook 423

If the magneto is at fault, all the cables and
terminals should be examined for improper con-
nections. The coil and battery system may then
be disconnected by removing the wires from
terminals Nos. 3 and 4 of the magneto, and with
a short piece of wire magneto terminal No. 3
may be connected directly with magneto ter-
minal No. 4. This will conduct the high-tension
current induced in the magneto direct to the
distributer. The grounding wire should then
be disconnected from terminal No. 2 of the
magneto. With this arrangement it should be
possible to start the engine on the magneto, and
it will be necessary to follow this plan should
any accident happen to the coil.

To ascertain if the magneto is generating cur-
rent, the grounding wire should be disconnected
from terminal No. 2 on the magneto, and the
high-tension wire should be disconnected from
the collecting ring terminal No. 3. If the engine
is then cranked briskly a spark should appear
at the safety spark gap that is located under
the arch of the magnets on the dust cover,
provided the magneto is in proper condition.
The grounding wire should then be reconnected
to terminal No. 2, and the engine cranked. If
no spark appears at the safety spark gap, the
trouble may be determined as a leakage of the
primary magneto current to ground by chafed
insulation, incorrect connections, or an injury
to the switch parts.

The coil may be tested by disconnecting wire

424 The Automobile Handbook

No. 4 from the magneto and throwing the switch
to the battery position, operating the press but-
ton with terminal No. 4 3/16 inch from the
metal of the engine. If the coil is in good con-
dition, a brilliant spark should be observed. If
the spark does not appear the test should be re-
peated with wire No. 3 disconnected. If the
fault persists the coil body may be removed
from the housing by withdrawing the holding
screw that is located close to the supporting
flange; the switch should then be unlocked and
the end plate given a quarter revolution. This
will release the bayonet lock and the coil body
may then be withdrawn to permit the inspection
of the switch contacts both of the coil and of
the stationary switch plate. It may be that the
•spring contacts are bent or otherwise in bad
condition. The withdrawing of the coil body
and its handling should be performed with ex-
treme care. No work should be done on the coil
in the way of withdrawing screws, etc., and if
the inspection does not disclose the fault the
coil should be returned to its housing and the
whole returned to the makers or to one of their
branches.

Bosch **NU" Magneto. Like other Bosch
high-tension magnetos, the type **NU4,** Pig.
187, generates its own high-tension current di-
rectly in the magneto armature (the rotating
member of the magneto) without the aid of a
separate step-up coil, and has its timer and
distributer integral. The distinct gear-driven

The Automobile Handbook

425

distributor common to other types has been
omitted in the "NU4" magneto, and in its stead
is a double slipping combining the functicais of
current collector and distributor.

The armature winding is composed of two
sections: one, primary, or low tension, consist-
ing of a, few layers of Comparatively heavy
wire, and the other, secondary, or high tension,
consisting of many layers of iine wire.

Pig. 187

Bosch High Tension Magneto, Model "NU"

The beginning of the primary winding is in
metallic contact with the armature core, and
the other, or live, end is connected by means of
the interrupter fastening screw to the insulated
contact block supporting the long platinum
screw on the magneto interrupter. The inter-
rupter lever, carrying a short platinum screw, is
mounted on the interrupter disc which, in turn,
is electrically connected to the armature core.
The primary circuit is completed whenever the

426 The Automobile Handbook

two platinum interrupter screws are in contact
and interrupted whenever these screws are sepa-
rated. The separation of the platinum screws is
controlled by the action of the interrupter lever
as it bears against the two steel segments se-
cured to the inner surface of the interrupter
housing. The high-tension current is generated
in the secondary winding only when there is an
interruption of the primary circuit, the spark
being produced at the instant the platinum in-
terrupter screws separate.

The secondary winding is insulated from the
primary, and the two ends of the secondary are
connected to two metal segments in the slipring
mounted on the armature, just inside the driv-
ing shaft end plate of the magneto. The slip-
ring has two grooves, each containing one of
the two metal segments. These segments are set
diametrically opposite on the armature shaft,
that is, 180 degrees apart, and insulated from
each other, as well as from the armature core
and magneto frame.

The four slipring brushes which are part of
the secondary circuit are supported by two
double brush holders, one on each side of the
driving shaft end plate, each holder carrying
two brushes so arranged that each brush bears
against the slipring in a separate groove. Upon
rotation of the armature, the metal segment in
one slipring groove makes contact with a brush
on one side of the magneto at the same instant
that the metal segment in the other slipring

The Automobile Handbook 427

groove comes into contact with a brush on the
opposite side of the magneto. The marks 1 and
2 appearing in white on both brush holders in-
dicate pairs of brushes receiving simultaneous
contact, those marked 1 constituting one pair,
and those marked 2 the other.

A spark is caused at two plugs simultane-
ously. It is important to note that as two of
the four slipring brushes receive contact simul-
taneously and each is connected by cable to the
spark plug in one of the cylinders, the secondary
circuit always includes two plugs, and the spark
occurs in two cylinders simultaneously.

After removing one of the brush holders to
permit observation of the slipring, the armature
shaft is rotated in the direction in which it is
to be driven, until the beginning of the metal
slipring segment is visible in the slipring groove
corresponding to Fig. 1 of the brush holder
which has been removed. With that done, the
cover of the magneto interrupter housing is to
be removed to expose the interrupter. The
armature shaft should then be further rotated
until the platinum interrupter screws are just
about to separate, which occurs when the inter-
rupter lever begins to bear against one of the
steel segments of the interrupter housing.

The armature should be held in that position
while the magneto drive is connected to the
engine, due care being taken that the piston of
No. 1 cylinder is still exactly on top dead center
of the compression stroke.

428

The Automobile Handbook

After the brush holder and interrupter hous-
ing cover have been replaced the installation is
completed by connecting the cable of one of the
brushes, marked 1, with cylinder No. 1, Fig. 188,
and the other with cylinder No. 4; the remain-
ing two cables, leading from the brushes, marked
2, must be connected with cylinders Nos. 2
and 3.

ff=\

3 C

I '

Pt > _2.

Ill
I 1

] C

!iv

«._,-- 1

1 c

> <

r-*--.

Li-J

' * I

Fig. 188

Wiring Connections for Bosch Magneto, Model

"NU"

Dixie ^Magneto. The Mason principle on
which the Dixie magneto operates is shown in
Fig. 189. The magnet has two rotating polar
extremities, N S, which are always of the same
polarity, never reversing. These poles are in
practical contact with the inner cheeks of the
permanent magnet M, all air gaps being elimi-
nated. Together with the U-shaped magnet,
they form a magn^ with rotating ends.

The Automobile Handbook

429

At right angles to the rotating poles is a field
consisting of pole pieces F and G, Fig. 190,
carry i^g across their top the core C and the
windings W. When N is opposite 6, the mag-
netism flows from pole N on the magnet to G
and through the core C to F.

Fig. 189
Dixie Magneto Principle

In Fig. 191 the pole N has moved over to F
and the direction of the flow of magnetism is
reversed; it now flowing from F through C to
G. The rotating poles do not reverse their
polarity at any time, consequently the lag due
to the magnetic reluctance in this part is elimi-
nated.

The magneto has a rotating element consist-
ing of two pieces of cast iron with a piece of
brass between them, but no armature of the
usual form, the revolving generating element
being shown in Fig. 192. The pieces N S are
separated by the brass block B and correspond
to the pieces N S in Figs. 189, 190 and 191. The
generating windings are carried on a small coil
placed across the upwardly projecting ends of
two pole pieces.

430

The Automobile Handbook

The core of the coil A, Pig. 193, is stationary;
and the inner end 6 of the primary winding
P is grounded on the core. Q indicates the
metal frame of the machine, which is put to-

MHh

Fig. 190 Pig. 191

Dixie Magneto Action Reversal of Magnetism

Through Dixie Magneto

gether with screws. The condenser R is located
immediately above the coil and is readily re-

Fig. 192
Rotating Element in Dixie Magneto

mova])le. The terminal D is a screw on the
head of the coil and the wire Z connects di-
rectly to the contact Y of the breaker. The
})reaker co^ stationary and do not re-

volve as i are type.

The Automobile Handbook

431

Fig. 194 shows the high tension circuit. Here
the end G of the high tension winding goes to
a metal plate D carried on the upper side A of
the coil. Against D bears a connection F, which
is practically one piece with the traveling con-
tact J, which connects to the spark plug seg-
ment L, the circuit being completed through the
spark plug, engine frame and frame of magneto
in the usual manner without brush G.

Fig. 193
Low Tension Primary Circuit of Dixie Magneto

The proper distance between the platinum
points when separated should not exceed 1/50 of
an inch, and a gauge of the proper size is at-
tached to the screwdriver furnished with the
Dixie.

The platinum contacts should be kept clean
and properly adjusted. Should the contacts be-
come pitted, a fine file should be used to smooth
them in order to permit them to come into per-
fect contact. The distributor block should be

432

The Automobile Handbook

removed occasionally and inspected for an ac-
cumulation of carbon dust. The inside of the
distributor should then be wiped dry with a
clean cloth. When replacing the block, care
must be taken in pushing the carbon brush into
the socket. The magneto should not be tested
unless it is completely assembled, that is, with
the breaker box, distributor cover and wires in
position.

I
I

Pig. 194
High Tension Circuit of Dixie Magneto

In order to obtain the most efficient results
with the Dixie magneto the normal setting of
the spark plug points should not exceed .025 of
an inch and it is advisable to have the gap just
right before a spark plug is inserted into the
cylinder. The spark plub electrodes may be
easily set by means of the gauge attached to the
screwdriver furnished with the magneto.

EisEMANN Magneto. There are two types of
the Eisemann magneto. First, the low-tension

The Automobile Handbook

^neto requiring a transformer to raise the
tage of the current; and second, the high

Fig. 195
iigh-Tension Magneto

sion magneto, which has a double winding
the armature and does not require a non-
rator eoil.

434 The Automobile Handbook

The low tension magneto gives off from 20
to 40 volts only. One end of the armature
winding is grounded, the live end passing to
the insulated contact of the interrupter, which
is located at the end of the armature shaft.
From this point the circuit continues to one
terminal of the primary, winding of the coil,
the other terminal of which is grounded. The
grounded part of the interrupter, a pivoted le-
ver, is operated by a cam carried on the arma-
ture shaft, and makes and breaks contact with
the insulated part. The cam is set in such re-
lation to the armature that the breaking of the
circuit by the interrupter coincides with the
production of maximum current in the arma-
ture winding. When the interrupter is making
contact, the magneto current is offered two cir-
cuits by which it may flow to ground, one
being through the interrupter and the other
through the primary winding of the coil. The
resistance of the former being low, the current
takes that path in preference to the other,
which is of higher resistance. When the cur-
rent reaches its maximum the cam breaks the
interrupter circuit, and the only path by which
the current can then flow to ground is that of-
fered by the primary winding of the coil. This
sudden and intense flow causes the core of the
coil to tlirow out a powerful magnetic field,
whicli indnoos a current in the secondary wind-
insr of from 20,000 to 40,000 volts. This current
is passed to the proper spark plug through the

The Automobile Handbook

435

medium of a distributer located ou the magnetx)
ajid driven by the armature shaft. A condenser
is connected across the interrupter contacts to
reduce the sparking as the circuit is broken,
and to effect a more abrupt change in the mag-
netic field of the coil.

General Wiring Diagram for Eisemann Magneto
A later Eisemann magneto is of the high-
tension type, as shown in Fig. 195, in which A
is the cam nut; B, steel contact for high-ten-
sion distributer; C, platinum contact for make-
and-break lever; D, high-tension distributer
cover; E, nut for adjustable contact screw:

436

The Automobile Haridbook

F, spring for make-and-break lever; G, carbon
eontaet for bigh-teneion distributer; H, make-
and-break lever ; I, low-tension carbon brusb ;
K, adjustable platinum contact screw ; L, grease
box for large toothed wheel ; M, nut ; N, cam ;
0, cable joints; P, distributer plate; Q, metal
contact ; S, screw for spring for make-and-
break lever ; V, high-tension distributer.

Fig. 197

Magnetos are made to turn in either direc-
tion, but the magneto once finished turns in one
direction only, and this direction is indicated
by an arrow placed on the gear wheel case.

The spark occurs in one of the cylinders at
the moment that the eontaet points are sepa-
rated by the cam. The advance mechanism is
arranged in three different ways: (1) by means
of a lever working the make-and-break mechan-
ism (quadrant advance); (2} by means of ft
piston sliding longitudinally, and fitted to th6

The Automobile Handbook

437

end of the driving axle (piston advance) ; (3)
by rocking the magnets bodily around the ar-
mature (pivoting advance). In all cases a dis-
placement of 45 degrees can be obtained. In
magnetos with quadrant advance the driving
spindle is fixed by means of a pin and nut.

This type of magneto is consequently shorter
than the one with piston advance. In the lat-
ter ease the driving, pinion. is fixed on a hollow

spindle.

Fig. 198
Pole Piece Coastructlon In Eleemann Magneto

The Eisemann dual system consists of a direct
high-tension magneto and a combined trans-
former coil and switch. The transformer proper
is used only in connection with the battery;
the switch is used in common by both battery
and magneto systems. The magneto is prac-
tically the same as the single ignition instru-
ment. Separate windings and contact breakers
are used for battery or magneto current. On
the other hand, parts that are not subject to
accident, or rapid wear, are used in common.

438

The Automobile Handbook

A distinctive feature is that the pole pieces
are of a certain shape, Fig. 198, whereby the
most extended portion thereof is approximately
opposite the theoretical axis of the winding
upon armature core. This construction results
in the flow of the magnetic lines of force being
drawn from the extremities of the pole pieces
towards the center of the core; a large volume
of the magnetic line of force is thus forced
through the winding.

PLATINUM CONTACTS

PRESSURE
SPRING

ADJUSTABLE

CONTACT
SCREW

CONTACT
SPRING

GROUND CARBON

Fig. 199
Breaker of Eisemann Magneto

The make-and-break mechanism, Fig. 199,
consists of a bronze plate on the back of which,
and cast in one piece with it, is a cone, fitting
into the armature shaft, which is bored out
and ])rovided with a key-way. It moves inside
of the timing lever and is fastened to the arma-

The Automobile Handbook 439

ture by means of the screw. If this screw is
extracted the whole mechanism can be removed.

The primary current is led from the winding
through the armature shaft to the contact screw
by the insulated screw, which also serves to hold
the mechanism to the armature shaft as already
described. When the armature reaches the cor-
rect position, a lever is lifted by two steel cams
fastened to the magneto body; the primary cir-
cuit is broken and the current is induced in the
secondary winding. The beginning of the sec-
ondary winding is connected with the end of the
primary winding, and the other end, through
several mediums, finally delivers the spark in
the cylinder.

In addition to this the magneto is also fitted
with the battery circuit breaker, which is mount-
ed at the back of the magneto breaker. It con-
sists of a steel cam, having two projections
which actuate a steel lever mounted into the
breaker housing.

A condenser is built in between the T-shaped
end of the armature and the bearing. This pre-
vents a spark occurring at the platinum con-
tacts with the consequent pitting and burning,
when the contact breaker opens, and it also in-
creases the intensity of the spark at the plugs.

The coil consists of a non-vibrating transform-
er and a switch, which is used in common to
put either the battery or magneto ignition into
operation. It is cylindrical in shape, compact.

440 The Automobile Handbook

and is placed through the dashboard. The end
which projects through on the same side as the
motor has terminal connections for the cables.
The other end, facing the operator, contains the
switch and the starting mechanism. The trans-
former proper is used only in conjunction with
the battery.

As the spark occurs when the primary circuit
is broken by the opening of the platinum con-
tacts, it is necessary that the magneto will be so
timed that at full retard the platinum contacts
will open when the piston has reached its highest
point on the firing stroke. To arrive at this, turn
motor by hand until piston of No. 1 cylinder
is on the dead center (firing point). Place the
timing lever of the magneto in fully retarded
position, then turn armature of magneto until
No. 1 appears at the glass dial of the distributer
plate, and make sure that the platinum contacts
of the magneto are just opening. Fix the driv-
ing medium in this position.

If no window is seen, turn motor by hand
until piston of No. 1 cylinder is on dead center
(firing point), remove the distributer plate from
the magneto and turn the drive shaft of the
armature until the setting mark on the distribu-
ter disc is in line with the setting screw above
the distributer. (For magneto rotating clock-'
wise use setting mark R, and for counter clock-
wise use mark L.) With the armature in this
position the platinum contacts are just opening
and the metal segment of the distributer disc

The Automobile Handbook 441

is in connection with carbon brush for No. 1
cylinder. The driving medium must now be
fixed to the armature axle without disturbing
the position of the latter, and the cables con-
nected to the spark plugs.

If a spark plug cable becomes disconnected or
broken, or should the gap in the spark plug be
too great, then the secondary current has no
path open to it, and endeavoring to find a
ground will sometimes puncture the insulation
of the armature of the coil. To obviate this, a
so-called safety spark gap is placed on the top
of the armature dust cover. It consists of 'pro-
jections of brass with a gap between them. One
of these is an integral part of the dust cover,
and therefore forms a ground. The other brass
part is connected with the terminal H M and
the secondary current will jump across the in-
tervening gap above mentioned, thus protecting
the armature secondary winding and the high
tension insulations.

In the coil, this safety gap is placed at one
?nd of the core, and hence is not visible. It
consists of a pointed brass finger, attached to
)ne end of the secondary, and pointing towards
he iron core of the coil.

The contact points may be cleaned with gaso-
line until the contact surface appears . quite
^^hite, or use a fine file, but very carefully, so
hat the surfaces remain square to each other.
The gap at the contact points should not amount
:o more than 1/64 inch and, as the contacts

442

The Automobile Handbook

wear away in time, they must be regulated now
and then by giving the screw a forward turn,
or eventually by renewing. When this platinum
tipped screw is adjusted, care must be taken
that the lock-nut is securely tightened in place.
By loosening the center screw, the whole inter-
rupting mechanism may be taken out, so that
the replacement of the platinum contacts with-
out removing the apparatus can be easily done
at any time. The fixing screw of the make-and-
break is held fast by a lock spring, so that it
is impossible for this screw to loosen. When it
is desired to remove this screw, the lock spring
must first be removed by turning it over the
head of the screw. Do not forget to put the
spring in the original position after having fixed
the make-and-break to the armature.

B A

Fig. 200

Automatic Advance Mechanism of Eisemann

Magneto

The Eisemann automatic advance. Fig. 200, is
accomplished ])y the action of centrifugal force
on a pair of weights A attached at one end to a
sk*ev(^ B, tlirough which runs the shaft C of the
magneto, and hinged at the other end to the
armature.

The Automobile Handbook 443

Along the armature shaft arm run two spiral
ridges which engage with similarly shaped
splines in the sleeve. When the armature is
rotated the weights begin to spread and exert a
longitudinal pull on the sleeve which in turning
changes the position of the armature with refer-
ence to the pole pieces. In this way the moment
of greatest current is advanced or retarded, and
with it the break in the primary circuit, for the
segments which lift the circuit breaker and
cause the break in the primary circuit are fixed
in the correct position and thus the break can
only occur at the moment when the current in
the winding is strongest. On magnetos without
this advance it is the segments which are moved
forward or back, as the case may be. As there
is only one actually correct position for the seg-
ments, every degree away from this weakens
the spark.

The spreading of the weights rotates the arma-
ture forward, and advances the spark and the
resumption, either total or in part, of their
original position close to the shaft, retards it by
rotating the armature backward.

As the timing is accomplished by changing
the relative positions of armature and motor
and not those of the segments in the timing level
which cause the breaking of the circuit, the
spark is always bound to occur at the moment
of greatest current and the apparatus thus
g:iven as strong a spark at retard as when fully
advanced.

444 The Automobile Handbook

As the speed becomes slower a spring D
brings the weights together again, so that by
the time the motor has come to rest the magneto
is fully retarded, this being the correct position
for starting.

Pig. 201
Magneto Used on the Ford Cars

In the rear end of the governor housing there
is a transverse slot into which fits a key, far-

The Automobile Handbook 445

nished with each magneto. When this key is
shoved in as far as it can go the armature is
fixed in the position where the platinum con-
tacts begin to open. The shaft is held tight in
the correct position and the coupling may be
screwed up with the assurance that the magneto
is correctly set and without danger of damag-
ing the armature.

446 The Automobile Handbook

FoED Magneto. The Ford ma^eto, Pig.
201, is of a peculiar design, it being constructed
as an integral part of the flywheel, in which A
is the support for the magneto coils; BBB, mag-
neto coils; CC, permanent horseshoe magnets;
DT>, the flywheel ; E, planetary pinions ; F, low
speed brake band ; G, reverse brake band ; H,
disc-clutch for high speed ; I, transuussion

brake ; J, clutch rocker shaft, and K, high speed
clutch spring. The permanent magnets, which
are U-shaped, are bolted to the forward face of
the flywheel, as shown In Fig. 202, Close in front
of their outer ends is a series of insulated coils
mounted in a circle of practically full flywheel
diameter, with their axes parallel with that of
the crankshaft. They are supported apon a
stationary spider, as shown in Fig. 203. As the
flywheel revolves, this magnet and coil com-
bination, which is similar to that used on some

The Automobile Handbook 447

types of alternating current generators, pro-
duces a current which is used through a four-
unit current timer to cause the ignition spark.
The magneto is of the inductor type, the arma-
ture coils being stationary, and the field mag-
nets moved past them. Sixteen separate field
magnets are used, made of vanadium-tungsten
steel. They are substantially horseshoe shape,
being secured to the side of the flywheel as illus-
trated in Fig. 203. They are held in place by
screws at their middle, and by clamps near their
poles, all screws used for fastening them being
securely locked in place by wire locks.

The magnets are so arranged that like poles
are adjacent to each other, forming a six-
teen pole field magnet crown. Instead of being
placed close against the flywheel, these mag-
nets are clamped against a ring of non-magnetic
material (brass for instance), in order to re-
duce leakage of magnetism through the fly-
wheel rim. At their middle these magnets are
fastened directly to the flywheel, as at this point
they are neutral, and there can be no leakage.
A series of sixteen armature coils is carried on
a coil supporting ring slightly in front of the
flywheel, as shown in Fig. 202. These coils are
wound with heavily insulated magnet wire, and
are so grouped around the supporting ring that
the winding of adjacent coils is in different di-
rections, one being wound clockwise, and the
next one counter clockwise. The coils are con-
nected in. series, the terminals being brought

448

The Automobile Hayidbook

out near the top of the casing. As the poles
of the niagnpts are located opposite and very
close to the coils, the magnetic circuits are com-
pleted by the cores of these coils and the coil
support. There are evidently sixteen electrical
impulses produced during the revolution of the
crankshaft and flywheel, although only two im-
pulses are required for the ignition of the mo-
tor, one per stroke. However, as the armature
circuit is closed only when a spark is wanted,

a current only flows at that period, and there
is no loss from the other impulses,

IIebz TTigh Tension JIagneto. This mag-
neto diffi'rs from the regular conventional type
in that it is cylindrical in shape, due to the em-
ployment of rinp-shaped field magnets A — ^Fig.
204 — instead of the horseshoe type generally
adopted. The six IIitz magnets are in reality
Hs many flat steel rings clamped together with
a polar space, or armature tunnel, C, cut in

The Automohile Bandbook

449

'he ring surfaces are ground with the
leeuraey in order to obtain the best
effect when they are all clamped to-
These magnets are mounted on an
a base S. A second unconventional-

at the usual independent, soft-metal
&s, which bolt to the ends of the horse-
nets in the conventional magneto, are
[ with entirely. In the Herz system
C, which accommodates the armature,

450 The Automoiile Handbook

is bored out from the magnets A, and in this
manner sharp angles in the magnet system,
which invariably result in a leakage of lines of
force in the magneto, are avoided. The arma-
ture D, Fig. 205, is of shuttle shape, accommo-
dating the low, and high-tension windings E
within the frame portion of it. So careful has
the construction of this armature been superin-
tended that there is but l-lO-millimeter air
space between it and the curved portions of the
magnets A. The armature revolves on ball-
bearings, mounted in special cages, and is fitted
with lubricating means sufficient for many
months' use. The armature windings consist
of a primary winding, in which is generated the
low-tension current and also a secondary wind-
ing in which is generated the induced, or high-
tension circuit. At one end of the armature,
and encased in a brass box, is the condenser, F,
Fig. 205.

The make-and-break devices for interrupting
the primary circuit are illustrated in Fig. 205,
the entire device being a detachable unit, which
secures to the armature shaft by a key-way and
feather. This make-and-break mechanism con-
tacts with one end of the primary winding of
the armature through a small carbon brush, fit-
ted into the contact disk, which presses against
a ring alongside of the ball race on the arma-
ture. The contact device consists of three
l^arts : First, a curved spring G, having a plat-
inum flat contact on one end; a steel block H

The Automobile Handbook

451

carrying an adjustable platinum contact, and
a small, hard-fiber roller K carried on a pin.
This roller is set so that if it is given a slight
push at the edge it tends to move up the in-
cline plane formed by the steel piece H, and in
doing so pushes against the end of the spring G
and separates the platinum contacts L. This

contact-maker revolves bodily with the arma-
ture, and in its rotation the fiber roller K strikes
upon two steel projections M — ^Fig. 206— held
in the case, thus breaking the circuit at the
points of maximum induction twice in each rev-
olution, at which time the induced current is
set up in the secondary winding of the magneto.
It is scarcely necessary to comment here that

452 The Automobile Handbook

the primary and secondary windings are
oughly insulated from each other, and
with the making and breaking of the prii
current an induced current is set up in the
ondary winding, which because of the i
turna of wire in this winding, is of a par
larly high voltage. For cutting off the s
when desired a terminal is provided on the
tact-maker case, which gives a connectio:
means of a spring pressing on the head

ig. 207
High- Tension End

steel screw in connection with the insu!
end of the primary winding, which thus
be short-eireuited at will. In advancini
retarding the spark, connections are made
tbc ball-ending N, Fig. 206, the contact-m
liiiving a 30-degrce movement for this pur
The high-tension end of the armature
iiHiiinted upon it a deeply recessed insul)
t'oljar, with a metallic sector within it. 1
this sector are small carbon brushes for d

The Automobile Handbook 453

ing off the high-tension current. In Fig. 207
appears a magneto suitable for a two-cyl-
inder engine with its high-tension terminals
R located at 90 degrees to each other. To ob-
tain the two sparks the high-tension contact
piece, orsector is fitted with an insulating col-
lar, which does not go quite half way round,
and thus makes alternate contact with the two
carbon brushes R, sending the spark to the re-
spective cylinder. In four-cylinders a distrib-
uter is combined. The safety spark gap is
located between the high-voltage sector and the
armature, and if the spark exceeds % inch it
bridges the insulating collar to the armature.

Mea Magneto. The most noticeable differ-
ence between the Mea magneto and other stand-
ard forms is that the magnets are bell-shaped
and are placed horizontally and with their axes
in line with the armature shaft. This is a dis-
tinct variation from the customary horseshoe
magnets plaijfed at right angles. This makes
possible the simultaneous movement of the mag-
nets and breaker instead of the advance and
retard of the breaker alone.

It will be seen that, as a result of this con-
struction, the relative position of armature and
field at the moment of sparking is absolutely
maintained, and the same quality of spark is
therefore produced, no matter what the timing
may be.

Fig. 208 shows a longitudinal section of a
four-cylinder instrument. In the bell-shaped

454 The Automobile Handbook

magnet 100, having the poles on a horizontal
line near the driven end of the magneto, rotates
armature 1 in ball bearings 17 and 18. The
armature consists mainly of an I-shaped iron
core, mounted on a spindle, and wound with a
heavy primary winding of a few turns and a
light secondary winding of many turns. On
this armature are also mounted the condenser
12, the collector ring 4, and the low-tendon

Fig. 208
Mea Magneto

breaker 26-39. The latter is built up of a disc
27, which carries the short platinum contact 33;
the other contact point 34 is adjustable and
supported by a spring 20, which in turn is fas-
tened to the insulated -pVale ^% Twsxm\a6. ■avi. Smk,
27. The breaker is actuated \i^ VVa 'cfet'& -t(S«a

The Automobile Handbook 455

31 in connection with cam disc 40, which is
provided with two cams and located inside the
breaker, being fastened to the field structure.
In revolving with the armature the roller
presses against the spring supported part of the
breaker whenever it rolls over the two cams and
in this manner opens the breaker twice every
revolution. Inspection of the breaker points is
made possible by means of .an opening in the
side of the breaker box, provided at the point
of the circumference at which the breaker opens.
The box is closed by a cover 74, supporting at
its center the -carbon holder 47, by means of
which the carbon 46 is pressed against screw 24.
This latter screw connects with one end of the
low tension winding, while the other end is
connected to the core of the armature. It will,
therefore, be seen that the breaker ordinarily
short-circuits the low tension winding and that
this short-circuit is broken only when the break-
er opens; it will also be apparent that when
the screw 24 is grounded through terminal 50
and the low-tension switch to which it is con-
nected, the low-tension winding remains perma-
nently short-circuited, so that the magneto will
not spark. The entire breaker can be removed
by loosening screw ?4.

The high tension current is collected from col-
lector ring 4 by means of brush 77 and brush
holder 76, which are supported by a removable
cover 91, which also supports the low tension
grounding brush 78 provided to relieve the ball

456 The Automobile Handbook

bearing of all current which might be injurious.
Cover 91 also carries the safety cap 89, which
protects the armature from excessive voltages in
case the magneto becomes disconnected from the
spark plugs.

The distributer consists of the stationary part
70 and the rotating part 66, which is driven
from the armature shaft through steel and
bronze gears 7 and 72. The current reaches this
distributer from carbon 77 through bridge 84
and carbon 69. It is conducted to brushes 68
placed at right angles to each other and making
contact alternately with four contact plates em-
bedded in part 70. These plates are connected
to contact holes in the top of the distributer,
into which the terminals of cables leading to the
different cylinders are placed.

In the front plate of the magneto is provided
a small window, behind which appear numbers
engraved on the distributer gear which corre-
spond to the numbers marked on the top of the
distributer. This indicator allows a setting or
resetting after taking out, without the necessity
of opening up the magneto to find out where
the distributer makes contact. Numbers on in-
dicator and distributer show the sequence of
sparks, not the numbers of cylinders which the
magneto is firing, as the sequence of firing
varies with different motors.

The variation of timing is effected by turn-
ing the magneto proper in the stationary base
which is accomplished through the spark lever

The Automobile Handbook 457

connections attached to one of the side lugs.
The spark is advanced by turning the magneto
in the direction of the rotation of the armature.

If the magneto is defective, the trouble will
usually be located in the breaker. The plati-
num contacts burn ofif in time and a readjust-
ment becomes necessary, -although this should be
the case only at very long intervals. The ad-
justment should be such that the breaker begins
to open with the armature in the position of
greatest current flow, and that the distance be-
tween contact points when fully open is about
1/64 inch or slightly more. The small gauge
attached to the magneto wrench may be used
for checking this adjustment. The small lock
nut of the contact screw must be tightened se-
curely after each readjustment of the contacts.

In addition any oil or dirt reaching the con-
tact points will in time form a fine film which
prevents perfect short-circuit of the low-tension
winding. If the condition of these points is
very bad, or if a complete inspection of the
breaker is desired, the latter should be removed
from the breaker box. This can readily be done
by loosening the long center screw holding the
breaker to the armature, and screwing it into
the small tapped hole provided in the breaker,
so that it may be used as a handle in lifting
the breaker out. The cleaning of the points
should be done with a fine crocus paper, or if
necessary, with a very fine file, after which a

458 The Automobile Handbook

piece of very fine cloth should be passed through
between the points so as to remove all sand or
filings. Special care must be taken not to round
off the edges of the contact points ; the satisfac-
tory operation of a magneto depends largely
upon the perfect contact at this point, and the
whole surface of the contacts should therefore
touch.

Fig. 209
Inductor Magneto Shaft

Remt Indtctor ir.iQNETO. This type of mag-
neto, now so e.tteiisively used for ignition pur-
poses, is a comparatively recent product, the
result of niiiny years of experiment and develop-
itivTit. Tlu' principli's of its action are as follows:
By ivvolving a solid steel shaft on which are
tw.i (Imp-forprtl steel magnet inductor wings,
a.s shown in Fig. 20ll. the magnetic field is

The Automobile Handbook 459

versed twice during each revolution, and

Bates two electrical current waves, or im-
Ises per revolution. The direction of flow
the magnetic current is changed at each im-
Ise, thereby generating an alternating cur-
it. A circular shaped stationary winding of
Lgnet wire is imbedded between the poles of

e magnets and around the inductor shaft,
d a strong current is generated in it and car-
id directly through the circuit breaking de-
ie by means of heavy lead wires, thus dis-
using with the use of carbon brushes and eol-
•toT rinps.

There are no revolving windings nor mov-
? contacts, and consequently many sources of

460

The Automobile Handbook

troohle are eliminated. The current is carried
to the transformer coil located on the dash-
board, where it is stepped ap to the high volt-
age necessary for creating the hot jump-spark.
From the transformer the current is con-
ducted back to a hard rubber distributer, see

Tlirou;;)! Inductor Tjrpe of Magneto

Fitr. 210, on the face of the magneto, and from
tlieiicc to the Hpnrli plugs. The distribater
shaft, located iiinnediatcly above the inductor,
i-evdivi's ii iiicfallic segment past the terminaki
of the wiri's h-jidiiifr to the spark plugs. The
hi^h fciision current is carried to this segment,
and traiiK]nilto<l to the sjmrk plug. A magneto

The Automoiile Handho^^ 461

this type, and gear-driven, gives what may
>perly be called perfect timing. A hot spark
ielivered in the cylinder under compression
the exact instant desired.
The device is also reliable for starting the
tor from the seat without cranking, for the
son that the motor always stops with the
gneto in such a position that the first spark
1 occur in the cylinder under compression
I where batteries are used a push button is
•vided, which by merely touching will cre-

the spark where needed. Fig. 211 shows a
tional view of the magneto. \
Ln important difference between the Remy
gneto just described and other models of the
uctor type is in the handling of the inductor
ghts. In models ''RD" and ''RL," each
uctor wing has been balanced by a bronze
ght fastened to the magneto shaft and on

opposite side of the shaft from the wing
t it compensates for. The weight, being
de of non-magnetic material, does not in any
Y affect the operation of the magneto elec-
»ally.

The inductor principle is not used in latex
dels of the Remy magneto, this feature being
'laced by an armature of the shuttle type
h a single low-tension winding. A sepa-
ely mounted transformer coil is used with
se instruments, this coil carrying a switch
t allows use of the current from the magneto
aature or from a set of dry cells or storage

462 The Automobile Handbook

battery, the current, from whichever eour'
passing though the same breaker, coil, distril
tor and plugs.

Tlie breaker of the new models is composed
a steel cam mounted upon and turning with l
armature shaft and which strikes against
contact piece in a pivoted arm that carries o
of the contacts of the breaker. £xcept for t

Pig. 212
Breaker Mechanism of Remy "RD" Hagneto

(iiovfinent reijuirod In altering the time of t
spark, the contacts and the pivoted arm rems
.stationary, the cam being the only revolvi
]>art ni tiic luralter mechanism. The condem
ihal is attached between the breaker contacts
carried in a housing tbat is mounted above t
inapni'fo armature and between the magnet lei
See Fig. 212.

r VA^ ^ 1*1 w v\^ ••v\^ \^ w«^ ^ ^ w • v«^ «^ ^ ^ •«

A device, known as a timing button, is incor-
porated on the Models '^P," **30," '^31" and

CO
fcO

N33ti9

i L^ ^-1

*'32** Remy magnetos, for the purpose of tim-
ing the magneto in connection with the engine.

Ttte Automobile Handbook

To set the magneto turn the ^igine crankshaft
until the piston of No. ] cylinder is at top cen-

ter after tlie compression stroke. Press in on
the tiitiiug button at the top of the distributor

The Automobile Handbook 465

turn the magneto shaft until the timing but-
is felt to drop into the recess on the dis-
iter gear. With the magneto in this posi-
make the coupling with the engine without
ng any attention to the position of the
ker cam. The location of the distributer
inal for the plug in No. 1 cylinder is deter-
d by the direction of rotation of the mag-
If the magneto runs clockwise, No. 1 ter-
l1 is at the lower left hand corner of the dis-
iter, while for anti-clockwise drive No. 1
inal is at the lower right hand corner. The
ig for the Models ''P'' and ''32'' is shown
^ig. 213, while the connections for Models
' and ''31" are shown in Fig. 214.
MMS Magneto. The armature is of the true
-tension type, on which is wound both the
:ension primary and high-tension secondary
lings, connected in series. The magneto
rates a high-tension current directly in the
iture, and does not use an exterior coil or
r device to step-up or transform the cur-
safety spark gap is provided to prevent
age to the magneto, in the event of one or
; of the high-tension cables becoming dis-
ected from the spark plugs. This gap is
)cated that its action may be readily ob-
id for the purpose of locating the cause of
ible misfiring.

le model "STJD" consists of a dual system
hich is provided a small hon-vibrating coil

466 The Automobile Hai Iboofc

which pan be either attached to the fra
(lanli of car, ae the coil is tmaffected by
rnuiHlure ot heat.

Th»f Hwiteh operating the battery circui
coiiticctiuii with the starting switch and
the Htarting pedal ig depressed (thereby
inK tli<; Htarting motor into operation) tt
rent (lows through the fswiteh eoil and ms

Fig. 215
Magnets and Extended Pole Pieces ol Sli

Magneto
As soon as the engine start8, or the st-
pedal is released, the circuit is automai
diseonneeted, and the engine runs on the
iicto. One of the principal features o
Siinnis magneto is the extended pole shoe, i
in Fig. 215.

The Automobile Handbook 467

To time the magneto to engine: Turn the
engine over by the starting crank until No. 1
piston reaches top dead center on compression
or firing stroke. Remove the dust cover, or if
a dual magneto, the commutator, and turn the
armature shaft until the figure 1 appears in the
"sight-hole" of distributor, Fig. 216. This
shows that that distributor brush is in contact

Fig. 216
Slmma High Tension Magneto

with distributor post 1. Retard the contact
breaker and move the armature, either to the
right or left, as occasion requires, until the plat-
inum points just break, or, in other words, just
separate. With the magneto in this position
couple it to the engine (to dead center on com-

468 The Automobile Handbook

pression stroke), and connect the remaining ter-
minals up in the proper firing order of the
engine.

For timing the model S U D, proceed as
above. The above instructions relative to en-
gine position apply also in this instance. The
only change is as follows:

For locating the position of the carbon brush
on No. 1 distributer segment, remove the dis-
tri])uter, which is held in place by means of two
spring clips, and turn the armature shaft* until
the distributer brush is brought into position,
namely, opposite No. 1 segment.

If the magneto is not firing, try the follow-
ing test. While the motor is running, discon-
nect one of the high tension cables from spark
I)lug, being careful not to touch the metal ter-
minal, and hold the cable with the terminal
close, about %" to 3/16", to any part of the
motor. This will show the strength of the spark
nnd each cable may be tested in turn. If the
matifneto is not delivering a good spark, examine
th(^ contact lireaker. The break or gap between
the platinnm points, when open due to the cam
action, shonhl correspond to the thickness of the
t?au<re furnished, which is approximately .015.

SpLiTDORF ]\Iagneto. The system used in old-
er models is that having an armature with .but
on(^ windinjr, and giving a current of compara-
tivi^ly low tension. The current is discharged
through a transformer having a low and a high-
tension winding somewhat similar to regular

•The Automobile Handbook

spark coil. This steps the current up to a volt-
age sufficiently high to enable it to jump the
necessary gap between the points of a spark
plug in the compressed mixture in the cylinder
of the motor.

The plain H, or shuttle, armature is mounted
between two annular ball bearings. Fig. 217.
One end of the shaft is the driving end and the
other is equipped with the breaker cam and the

Fig. 217
Section Through Splitdorf Magneto

insulation plug which delivers the current gen-
erated in the armature to the collector brushes
from which it is transmitted to the transformer
connection.

From A, Fig. 218, the armature current goes
through the primary of the transformer, return-
ing through the binding post No. 2 to the con-
tact screw bracket on the breaker box. No. 3 is
a common ground connection for both the mag-
neto and transformer. The circuit being broken

470

The Automobile Handbook'

at the proper moment, a very high voltage cur-
rent is induced in the secondary winding of the
transformer, and being delivered to the heavily
insulated cable D, is conducted to the central
brush of the distributor, whence it is delivered
to the spark plugs in the diflEerent cylinders in
correct sequence.

Wiring of Model "

Splitdorf Magneto

In addition to using the current from the
magneto, the transformer may he used as a
spark coil by using the breaker mechanism of
the magneto in the circuit to interrupt a cur-
rent from the battery, which can be switched
in for starting purposes or for an emergency.
The distributor is used to deliver the current
thus generated to the spark plugs. This gives a
dual system with one set of spark plugs, and
the movement of t!ie switch controls both sys-
tems. Fig. 219.

The Automobile Handbook 471

A later development is the new standard
"T S" type of transformer. Fig. 220, which
has practically superseded all other types, par-

Pig. 213
Wiring of Splltdorf Magneto With TranBtormer

Coil
ticularly as it does away with the separate
switch and still leaves the dash free. Both leads
from the battery must run direct to transformer.

472 The Automobile Handbook

After securing the magneto to the prepared
base on the motor, crank it until cylinder No.
1 is exactly on its firing center (i. e., the point
of greatest compression. The motor must re-
main in this position until the balance of the
work is finished.

Retard the spark advance mechanism at the
steering wheel to its limit and connect it to the
spark advance lever on the breaker box of the
magneto, so that if the magneto shaft revolves
in a clockwise direction looking at the driving
end, the breaker box lever will be at its top-
most position. If the shaft revolves left-handed
the lever should be at the bottom limit, and ad-
vanced upward.

Now revolve the armature shaft in its direc-
tion of rotation until the oval breaker cam
comes in contact with the roller in the breaker
bar and begins to separate the platinum contacts.

If it is desired to start on the magneto side,
ignoring the battery entirely, advance the spark
mechanism about one-half or two-thirds of the
wav and crank as before. No back kick should
be ol)served. Do not drive the motor with the
spark retarded, but as far advanced as the
motor will permit.

If th(^ platinum contacts after much usage
become pitted so that a bad contact results,
they can l)e filed flat with a fine file, taking
care not to file off any more than is necessary.
Then reset the screw so that the break is not
more than .025 of an inch.

The Automobile Handbook 473

Don't forget to occasionally brush the dis-
tributer disc and interior of distributer block
clean of any accumulation of carbon dust.

The **E U" magneto is a new high tension
machine designed for four cylinder motors de-
veloping as high as 40 horse power.

The construction of this magneto embodies
an aluminum base to which the pole pieces are
secured, and between which revolves an arma-
ture on two annular ball bearings. The circuit
breaker is attached to one end of the armature
shaft and revolves with it. The magneto is
self-contained, having both a primary and sec-
ondary winding on the armature.

The high tension winding of the armature is
connected to a collector ring, imbedded in a
spool mounted on the driving end of the arma-
ture shaft. From this ring a carbon brush leads
the current through a water-proof holder to the
center of the distributer disc.

The cam holder may be shifted to the extent
of 30 degrees, enabling an advance or retard of
the spark to be obtained, thereby causing igni-
tion to take place earlier or later.

The condenser necessary for the protection of
the platinum points and the proper functioning
of the machine is placed in the driving head of
the armature and revolves with it.

The distributer consists of a disc of insulating
material having a metal segment to which the
high tension current is led from the collector
brush. The distributer block has four small

474 The Automobile Handbook

carbon pencil brushes which lead the current
the brass connection imbedded in the block,
which the plug wires are fastened. The poj
tion of the segment on the disc can be sec
through the little window in the face of ti
distributer block for the purpose of setting tl
machine when timing.

A spark gap for the protection of the armi
ture winding is located at the inside end of tl
brush holder under the magnets.

The main bearings of the magneto are pr<
vided with oil <:ups, and a few drops of ligl
oil every 1,000 miles are sufficient to lubrical
them. The breaker arm should be lubricate
with a drop of light oil applied with a toothpic
to the hole in the bronze bearing pivoted o
the steel pin. The cams are lubricated by a fe
packing, and a little oil applied to the holes i
the edge of the cams wil. last a long time ; ar
surplus oil should be removec and care take
to prevent any oil getting on the platinu
points.

The proper distance between the platinu
points when separated should be .020 or 1/50 <
an inch. A bronze gauge of the proper size
attached to the wrench furnished for the adjus
mont of the platinum screw and lock nut.

The fibre roller on the end of the breaker ar
is held in position by a pawl spring. The wea
ing surface of the roller may be renewed 1
rotating the same a quarter turn, thus bringii
a new surface to bear on the cam, and as the

The Automobile Handbook 475

are four slots in the roller four wearing surfaces
are available.

To time the magneto, rotate the crank shaft
so as to bring the piston No. 1 cylinder 1/16
of an inch ahead of the upper dead center of
the compression stroke. With the timing lever
fully retarted, the platinum points of the cir-
cuit breaker should be about to separate. Some
motors may require an earlier setting.

The distributor segment should show in the
little window in the block and the plug wire to
No. 1 cylinder should be fastened under the
brass nut directly over the segment. The rest
of the plug wires should be fastened in turn
according to the proper sequence of firing of
the cylinders to which they lead.

U AND H Magneto. The particular feature of
this magneto, is that the starting spark is a
maximum, whether the crank is turned slowly
or fast.

In the operation of the U and H magneto.
Fig. 221, a low-tension current of electricity is
generated by the rotation of the armature of
the magneto. An interrupter, or timer, inter-
rupts the flow of this low-tension current at the
proper time, this interruption causing a high-
tension current, similar to that delivered by the
induction coil of a battery ignition system, to
be induced in the rotating armature by a pe-
culiar arrangement of the windings of the arma-
ture. The high-tension current is conducted to
a so-called distributer, the duty of which is to

476

The Automobile Handbook

distribute the high-tension current to the spark
plugs of the various cylinders in the proper se-
quence of firing. The wiring diagram of the U
and H magneto is shown in Fig. 222.

Kg. 221

U. & H. Magneto

The maRnefo consists of three pairs of per-
manent horseshoe magnets, placed parallel,
and having secured to each of their free enda
a soft iron block. These blocks are exactly

The Automobile Handbook

477

ike, and form a permanent magnetic field,
ley are bored so as to allow an armature to
volve between them. The armature is of the
uttle type, and is provided with a double

Inding. The inner or primary winding eon-
5ts of a few layers of coarse insulated wire,
le outer or secondary winding consists of a
•eat number of layers of fine insulated wire,
tie beginning of the primary winding is

478 The Automobile Handbook

grounded to the armature itself. The end
the primary winding is connected with i
carbon brush 1, which is carefully insulai
from the armature shaft. Brush 1 bears agai
the interrupter block screw 2, which in ti
conducts the current to the interrupter block
and to the condenser plate 4. From the int
rupter block 3 the current is conducted
means of the platinum pointed interrupter C(
tact screw 5 to the platinum contact on 1
interrupter lever 6. The interrupter lever
has metallic contact with the body of the m\
neto, and is therefore grounded and in el
trical connection with the beginning of the p
mary winding. It will be seen that when 1
interrupter lever 6 is in contact with intern
ter contact screw 5, the primary circuit
closed, and the primary winding of the arr
ture is short-circuited.

The beginning of the secondary winding
connected to the end of the primary wind!
being in fact a continuation of the primj
winding. This fact should be borne in mi
fis it has direct bearing upon the results
tained with this magneto. The end of the g
ondary winding is connected to the armat
slip ring 7, which is thoroughly insulated fr
the armature. From the armature slip rini
the current is conducted by means of
brushes 8-8 to the distributer slip ring 9, fr
whence it is led to the distributer brush 10
means of the distributer brush spring seat

The Automobile Handbook 479

The distributer plate 13 is provided with as
many brass distributer segments 14, evenly
spaced around the distributer bore, as there are
cylinders to be fired, and as the distributer
brush is revolved it comes into contact in suc-
cession with the segments. These segments are
in turn connected with the secondary terminals
15, located at the top of the distributer plate,
one terminal for each cylinder. From these
terminals the high tension current is conducted

by cables to the spark plugs of the cylinders,
from whence, after jumping the gap it is con-
ducted to the grounded end of the primary coil,
through the primary coil to the beginning of
■ the secondary winding, thus completing the sec-
ondary or high tension circuit.

U AND H Intekkupteb. The interruption of
the primary circuit is accomplished by the in-
terrupter, as shown in Pig. 223. This device
consists of the interrupter plate 16, which is

480 The Automobile Handbook

located in the interrupter 17. Attached to the
interrupter plate 16 is a stud 18, upon which
is pivoted the interrupter lever 6. The inter-
rupter lever is provided with a platinum
pointed contact screw 19, which is normally
held by the flat spring 20 in contact with the
platinum pointed interrupter contact screw 5.
The interrupter contact screw 5 is connected to
the end of the primary winding, as already de-
scribed.

Keyed to the interrupter end of the armature
shaft, and rotating positively with the arma-
ture, is the interrupter cam housing 21. Se-
curely attached to the interrupter cam housing
is the interrupter cam 22, consisting of a ring
of hard fiber, having on its inner face two pro-
jections or cam faces 22A.

The interrupter housing 17 is held in accu-
rate alignment with the interrupter cam 22 by
the construction of the rear end plate 23, and
as the armature revolves the projections 22A-
22A are brought into contact with the interrup-
ter cam pin 24, causing a movement of the in-
terrupter lever 6 sufficient to separate the con-
tact screws 5-19, and thereby interrupt the pri-
mary circuit twice in every revolution. As the
projections 22A continue to revolve, the inter-
rupter lev(T 6 instantly resumes its normal po-
sition, and completes the primary circuit. The
entire housini? of the interrupter is easily re-
moved for inspection, or adjustment by push*
ing the spring clip 31 to either side.

The Automobile Handbook 481

Induction Coil. The form of coil generally
used on gasoline cars is known as the jump-
spark coil. It is of two types, one known as a
plain or single jump-spark, the other as a vi-
brator or trembler coil.

A jump-spark coil consists essentially of a
bundle of soft iron wire, known as the core,
over which are wound several layers of coarse
or large size insulated copper wire, called the
primary winding. Over this are again wound
a great many thousand turns of very fine or
small wire, known as the secondary winding.

Inertia. Inertia is that property of a body
by which it tends to continue in the state of
rest or motion in which it may be placed, until
acted upon by some force. As used by the non-
technical, it is almost universally employed in
the former sense, i. e., that of the resistance
which a body offers against a change in its po-
sition, an inert body usually being intended, so
that the definition is perfectly correct so far
as it goes. The popular impression is that only
inert bodies have inertia, it being likewise gen-
erally thought that a moving body is possessed
of momentum alone, whereas an object at rest
is possessed of inertia, and the same object in
movement has both momentum and inertia.

Insulating Material. Asbestos, lava, and mica
are severally used for the insulation of spark
plugs and sparking devices.

Vulcanized fiber or hard rubber or even hard
wood are used for the bases of switches, con-

482 The Automobile Handbook

nection boards and other places.

India rubber, or gutta-percha form the
of the insulated covering of wires used for
trical purposes. The coils of small magnets
the cores of induction coils are usually wi
with cotton covered wire, or in some insti
the fine wire is silk covered, as in the cas
secondary or jump-spark coils.

Joints, Ball and Socket. To produce a de:
joint capable of operation within certain
tations in any direction, the ball and st
form of joint is generally used on the enc
the rod which connects the arm of the stee
mechanism with the steering lever attache
the hub of one of the steering pivots of
front axle.

COMPENSATING DEVICE

Fig. 22*

Joints, Compensating. On account of

distortion of the frame or running gear o

The AutomoMle Handbook

483

automobile, due to unequal spring deflection
and irregularities of the road surface, means
should be provided to insure flexible joints or
connections between the various rotating parts
of the mechanism of a car. The device shown
in Figure 224 is not susceptible to any great
amount of angular distortion, but will transmit
power with a practically uniform velocity, with
the axes of the shafts considerably out of align-

(•:

KNUCKLE JOINT

Fig. 225

ment in vertical or horizontal parallel planes.

The form of compensating joint shown in
Figure 226 may be operated with the axes of
the shafts at an angle to each other, or with the
shafts out of alignment with each other in ver-
tical or horizontal parallel planes, and has quite
a range of operation with either condition. Both

484

The Automobile Handbook

Fig. 226

forms of the device require to have bearings on
either side, as shown, to insure their proper
working.

Fig. 227

The Automobile Handbook 485

486 The Automobile Handbook

Joints, Knuckle. Swivel or knuckle-jointa
for connecting the steering arm of the wheel, or
lever steering mechanism to the arms on the
knuckle-joints of the steering wheels are of va-
rious forms. Figures 225 and 227 show knuckle-
joints which may be used for the above pur-
pose. They are of simple construction and
practically inexpensive to make. They may lie
used with any standard drop-forged jaw-ends.

Joint — Universal. The elementary form of a
universal-joint or flexible coupling consists of a
spiral spring. Such a form of universal-joint is
sometimes used to drive a rotary pump, or a
small generator on a car. The rear wheels or
axle of a car are sometimes driven by means of
a longitudinal shaft with a quarter-turn drive
on a counter shaft, or a bevel gear drive at-
tached to the differential gear of the rear axle.
In such cases some form of universal-joint is
necessary to allow the rear wheels and axle to
accommodate themselves to the inequalities of
the road surface. Three forms of universal-
joints are shown in Figure 228. The upper view
in the drawings shows the form most generally
used on motor-cars, for the purposes just de-
scribed. The one shown in the center view will
allow a greater amount of angular distortion
than the form sho^vn in the upper view, but is
of a more expensive construction. Where only
a slierht amount of angular distortion is needed,
the construction shown in the lower figure in
the drawincr i? ver>' suitable, the two jaws or

The Automobile Handbook 487

knuckles of the joint being flexibly attached
by means of a plate of spring steel.

A form of universal joint, or flexible coup-
ling, of recent introduction, is that making use
of leather or other flexible material securely
fastened to two forked members in such a way
that with the members placed at an angle to
each other, power is delivered from one to the
other through the flexible material that is
fastened to both of them.

Large powers are transmitted in this way by
using a ring of heavy material similar to tire
fabric and fastening the couplings of the two
shafts to this ring at alternate positions by
secure fastenings and bolts. The difference in
alignment is taken care of by the ring of flex-
ible material, and it has been found that this
form of drive is quite free from trouble, and,
of course, requires neither lubrication or cover-
ing against dust and dirt.
Kerosene as a Fuel. Kerosene has been used
as. an explosive power, and crude petroleum is
gaining favor as an efficient liquid fuel. With
a specific gravity varying from 0.78 to 0.82,
and a vapor flashing point at 120 to 125 de-
uces Fahr., kerosene ignites at 135 degrees ,
Pahr., and boils at 400 degrees Fahr. Its vapor
is five times heavier than air, and requires 76
cubic feet of air to one cubic foot of vapor for
its combustion, giving 22,000 heat units per
pound, or 4,000 more than gasoline.

Kerosene as a Cleansing Agent. Kerosene

488 The Automobile Handbook

injected into a motor cylinder and allowed to
remain over night will remove all deposit from
the piston head. It should then be blown out
through the relief-cock or the exhaust-valve.

Knight Engine. See Engine, Knight.

Knocking — Locating Cause of. Tracing a
knock is sometimes a puzzling job. It may be
in one of the main bearings of the engine, in
the camshaft bearings, in a loose valve lifter,
in a loose camshaft gear key, in a loose pump
or magneto drive coupling, an unsuspected
loose bolt between two parts supposed to be
fast, or in any of a dozen, or score of other un-
suspected places. A valuable aid in locating a
mysterious knock is a flexible speaking tube
such as is used with phonographs. One end of
such a tube can be held to the ear and the
other moved about from point to point until
the exact spot is found where the noise is loud-
est. Another aid is a light bar of iron, one end
of which is pressed against the part where the
knock is suspected and the other touched to the
forehead or the teeth, when the sound is clearly
transmitted.

Knocking or pounding is an inevitable warn-
ing that something is wrong with a motor. It
may be due to any of the following causes :

Premature ignition : The sound produced by
premature ignition may be described as a deep.
heavy pound.

losing a poor grade of lubricating oil will
caus(^ promaturo ignition. The carbon from the

The Automobile Handbook 489

oil will deposit on the head of the piston in
cakes and lumps, and will not only increase the
compression, but will get hot after running a
short time and will ignite the charge too, early,
and thereby produce the same effect as advanc-
ing the spark too much. If this is the cause the
pounding will cease as soon as the carbon de-
posit is removed from the combustion chamber.

Badly worn or broken piston-rings.

Improper valve seating.

A badly worn piston.

Piston striking some projecting point in the
combustion chamber.

A loose wrist-pin in the piston.

A loose journal-box cap or lock-nut.

A broken spoke or web in the flywheel.

Flywheel loose on its shaft.

If the spark plug be placed so as to be ex-
actly in the center of the combustion space, an
objectionable knock occurs, which has never
been fully explained. In some motors it ren-
ders a particular position of the spark control
lever unusable; this form of knock disappears
either on making a slight advance or retarda-
tion of the ignition.

Explosions occurring during the exhaust or
admission stroke. This is almost always due to
a previous misfire, and it is prevented by stop-
ping the misfires.

If the ignition is so timed that the gases reach
their full explosion pressure during the com-
pression stroke, that is, if the spark be unduly

490 The Automobile Handbook

advanced when the motor is not running at a
high speed, an ugly knock occurs, and great
pressure is developed on the crank-pin bearing,
wrist-pin, and connecting rod. The result may
be the bending or distorting of the rod.

The crank-pin may not be at right angles to
the connecting rod.

The bearings at either end of the connecting
rod may be loose. A knock during the explo-
sion stroke, and also at each reversal of the
direction of the piston.

If the crank shaft is not perfectly at right
angles to the connecting rod, the crank shaft
and flywheel will travel sideways so as to strike
the crank shaft bearings on one side or the

other.

Lamps, Electric. The small incandescent
lamps used for automobile lighting are almost
invariably of the tungsten filament variety.
Two types are in use, considered from the bulb
standpoint, one of which exhausts the air from
the ])ulb until a high degreei of vacuum is
secured, and the other one of which replaces
the air with the inert gas, nitrogen. One is
called the vacuum bulb and the other the nitro-
pren ])ulb. Two types of bulb base are in use.
the single contact, in which one side of the cir-
cuit is secured through metal of the base, and
tho (louhh^ contact with two insulated leads.
Lamp bulbs vary in diameter from % to 2-1/16
inclu'S.

Lighting, seo Starting and Lighting Systems.

The Automobile Handbook 491

Lubrication. To ensure easy running, and
reduce the element of friction to a minimum it
is absolutely necessary that all surfaces rubbin,fij
together should be supplied with oil or lubri-
cating grease, but it is also a fact, not so well
understood, that different kinds of lubricant
are necessary to the different parts or mechan-
isms of a motor car.

As the cylinder of an explosive motor oper-
ates under a far higher temperature than is
possible in a steam engine, consequently the oil
intended for use in the motor cylinders must
be of such quality that the point at which it will
burn or carbonize from heat is as high as possi-
ble.

While a number of animal and vegetable oils
have a flashing point, and yield a fire test suf-
ficiently high to come within the above require-
ments, they all contain acids or other sub-
stances which have a harmful effect on the
metal surfaces it is intended to lubricate.

Lubricating Oils. The qualities essential in
a lubricating oil for use in motor cylinders in-
clude a flashing point of not less than 500 de-
grees Fahrenheit, and fire test of at least 600
degrees, together with a specific gravity of 25.8.

At 350 to 400 degrees Fahrenheit, lubricating
oils are as fluid as kerosene, therefore the ad-
justment of the feed should be made when the
lubricator and its contents are at their normal
heat, which depends on its location in the car.
Steam engine oils are unsuitable for the dry

492 The Automobile Handbook

ueat of motor cylinders in which they are de-
composed whilst the tar is deposited.

All oils will carbonize at 500 to 600 degrees
Fahrenheit, but graphite is not affected by
over 2,000 degrees Fahrenheit, which is the ap-
proximate temperature of the burning gases in
an explosive motor. The cylinder of these mo-
tors may attain an average temperature of 300
to 400 degrees Fahrenheit. So that graphite
would be very useful if it could be introduced
into the motor cylinder without danger of clog-
ging the valves, and could be fed uniformly.
These difficulties have not yet been overcome.
Graphite is chiefly useful for plain-bearings and
chains.

The film of oil between a shaft and its bear-
ing is under a pressure corresponding to the
load on the bearing, and is drawn in against
that pressure by the shaft. It might not be

■

tlion^lit ])ossible that the velocity of the shaft
nnd the adhesion of the oil to the shaft could
produce a sufficient pressure to support a heavy
load, ])ut the fact may be verified by drilling a
hoh^ in the bearing and attaching a pressure
gau^ie.

K()ll(»r and ball-bearings provide spaces, in
which, if the oil used contains any element of
an oxidizing or gumming nature, a deposit or
nil adhesive film forms upon the sides of the
chamber, the rollers or balls, and the axle. This
dc^posit will add to the friction, hence it is the

The Automobile Handbook 493

more important to use a good oil, or a petro-
leum jelly in such bearings.

Air-cooled motors, being hotter than water-
cooled, must have a different lubricant, or one
capable of withstanding higher temperatures.

The effect upon animal or vegetable oils of
such heat would be to partially decompose the
oils into stearic acids and oleic acid and the con-
version of these into pitch. Such oils are there-
fore inadmissible for air-cooled motor use.

Mineral oils are not so readily decomposed
by heat, but at their boiling points they are
converted into gas, and any oil, the boiling
point of which is in the neighborhood of the
working temperature of the motor cylinder, is
useless, as its body is too greatly reduced to
leave an effective working film of oil between
the cylinder and the motor piston.

The essentials for the proper lubrication of
air-cooled motors are :

That the oil should not decompose.

That it should not volatilize, as this will re-
sult in carbon deposits.

That its viscosity should be equal to that of
a good steam engine oil at similar temperatures.

That it should be fluid enough to permit of
its easy introduction into the cylinder.

That it will have no corrosive effect on the
cylinders and no tendency to gum.

That it will not oxidize with exposure to air
and light.

Ltjbbtcattng Devices. Some makers of verti-

494

The Automobile Hmidbook

cal cylinder motors use the splash system,
whereby oil fed by gravity from a tank above
the level of the crank-case flows into the crank-
case, whence it is splashed over the piston and
the wrist and crank-shaft bearings. The large
end of the connecting rod, which works in the
crank-case, is made to dip or splash into a bath
of oil. This lubricates the crank-pin. The
splashing is invariably utilized to lubricate the
cylinder by wetting the bottom of the piston

Fig. 229

and splashing into the cylinder. A little ring is
sometimes made in the crank-case, into which
the oil collects and into which also the end of
the piston dips.

Fig. 229 shows a vertical cylinder motor using
splash lubrication.

The various methods of oiling outlined under
Luhrication Systems should be noted, inasmuch
as they give the principles by which any sys-
tem may be classified. Practically all appli-
cations are modifications of one or the other.

The Automoiile Handbook

McCord Mechanical Oiler. A, Center Post. B,
Worm Wheel. C, Drive Shaft. D, Plunger,
E. Yoke. F, Cam. G, Plunger Spring. H,
Adjusting Screw. I. Bashet, J, Center Poet
Spring. K, Spring Guide. L, Spiaer. M, Stuff-
ing Pad. N, StufTing Box. O, Gland Lock Nut.
P, Stuffing Gland. Q, Bleeder Nut. R, Spider
Lid Screw. S, Lid Screw. T, Lid Frame. U,
Safety Ratchet. V, Oil Inlet Port.

496 The Automobile Hatidbook

The number of feeds used varies on the dif-
ferent cars from two to fourteen, depending
upon the number of cylinders and bearings
used on the engine. In a six-cylinder car, it is
usual to find four feeds going to the crankshaft
bearings, six to the cylinders, three to the
cranhcase, and one to the fan bearing.

Fig. 231
Hancock Mechanical Oiler

When mechanical oilers are used for labri>
eating the motor, the erank-case is usually di-
vided into partitions, most of them dividing it
into halves, one compartment for the two front
cylinders and the other for the two rear cylin-
ders. Sometimes three partitions, giving four
compartments, are used. This arrangement
gives one portion for each connecting rod.
When this construction is used, the center par-
tition will be found higher than the other two.

A force feed lubricator usually consists of
an oil tank through which passes a shaft, which
has a slow, but constant motion throi^h me-

The Automobile Sandbook 497

chanical connection with the engine. This shaft
successively operates by means of cams, or oth-
erwise, a series of small piston pumps, usually
submerged in the oil, each pump feeding an oil
tube. The piston displacement of each pump
may be adjusted independently by changing the
length of stroke so that any amount of oil de-
sired may be delivered. Each pump stroke cor-
responds with a definite number of engine
strokes.

In some systems of force f^ed lubrication the
oilers are made without valves, double plungers
being used to force oil to the sight feeds, and
drawing positively, from the sight feed and
forcing to the delivery points.

The Hancock lubricator, Fig. 231, is of this
type, and action is as follows : Worm A drives
worm gear B and the shaft to which it is at-
tached. On this shaft are two eccentrics C
which impart a reciprocating motion to rod D
carrying rocker arms E, and E'. To one end
of these arms are fastened pistons F, and F'.
The crank G is secured to the taper shaft H,
and through connecting rod J a rocking mo-
tion is transmitted. This taper shaft H is pro-
vided with holes K, which on the suction stroke
register with the openings L, and \J, and the
pistons, and on the forcing stroke with open-
ings M, M, and the pistons. The arrows indi-
cate the direction of flow of the oil to delivery
points, the quantity being regulated by con-
trolling the stroke of piston F through the lost

498

The Automobile Handbook

motion allowed between the stop rod L and :
ulating piece 0. P is the regulating acrew, j
vided with a projection Q, which fits firmly :
the upper end of piece 0, forming a posi
locking device Shaft H is equipped at
end with a sprmg R which holds it to its s

At the other end, washer S and two lock-nu
and T' hold the shaft in its correct posil
Th(! shaft is thus allowed to run free in its g
rcfiiiiring but little power. Any number
fi'pds from one to sixteen may be used to ^
aniiinst pressure. In the Lavigne meehai
oiler, Fig. 232, the pumps are without c\

The Aviomobile Handbook 499

valves, or springs of any kind. The plungers
P, are raised and lowered by arms A attached
to the drive shaft. On the up stroke a- certain
quantity of oil is drawn into each pump cylin-
der, and on the down stroke this quantity is dis-
charged.

At the base of each plunger is an oscillating
valve V, which, as illustrated, has the opening
0 ready for the up stroke, so that oil may be
drawn from the reservoir into the plunger. Be-
fore the down stroke begins, the valve is oscil-
lated by a cam device so that the entrance O is
closed and the oil is directed through the lead
L, which connects with the bearings. There is
a time when the plunger L, is stationary at the
top, and also at the bottom of the stroke, which
is achieved by the cross head H, which raises
and lowers the plunger. This cross head slides
on the plunger until it contacts with a lower
shoulder S and an upper one T. And during
the period of no movement of the plunger the
valve V is being oscillated to be ready to open
the entrance 0 for intake stroke, and another
passage for the expulsion stroke.

The Pierce- Arrow oiling system, Fig. 233, is
partly positive, and partly gravity. The oil
pump is positively driven from the engine, and
pumps the oil from the crank chamber up into
the reservoir located on the engine. Pipes lead
from this reservoir to every crankshaft bear-
ing, the flow to the bearings being by gravity
under a head of twelve inches, which corre-

500 The Automobile Handbook

sponds to a pressure of about six ounces. The
crankshaft bearings are drilled hollow, and in
this way the erankpins and large ends of the
connecting rods are lubricated, A gauge is
usually placed on the dash to indicate the quan-
tity of oil in the reservoir.

The Pierce system does not allow any oil to
1 in the crankcase, the oil flying oflE the

erankpins beiiip sufficient to lubricate the cyiin-
dors. As there is ahvnys a mist of oil flying
around in the crankcase, it is known as the
"mist" system.

As shown iu Fifr. 2^3 the oil supply is car-
rii'il in a siiiup K bcin'titli th<' crankcase, and
thf cranki'aso bottfun is sloped towards the
center so ihiit oil fallinff in it is immediately

The Automobile Handbook 501

drained into the sump. The gear pump P,
driven from the camshaft through a vertical
shaft, elevates the oil to a tank T carried above
the cylinder heads, and from this a lead L
passes direct to each of the crankshaft bearings.
From these bearings the oil passes through the
drilled crankshaft to the lower bearings of the
connecting rods, whence any overflow falls into
the crankcase, or is thrown into the cylinders
in the form of a mist through the slot in the
baffle plate, closing the lower end of the cylin-
der to prevent an excess of oil getting on the
walls. This mist not only cares for the cylin-
der walls, but also oils the wrist-pin bearing.
The flow of the oil through the leads L from the
tank to the bearings is regulated by thimbles
]M, inserted in the upper ends of the leads where
they enter the oil tank, and in each thimble is
a small opening which allows only a limited
amount of oil to flow. The size of the openings
in the thimbles is varied to suit the demand of
the bearings for oil.

Flywheel Oiling Systems. In the Ford fly-
wheel system of oiling illustrated in Fig. 234,
the flywheel casing serves as an oil reservoir,
and the rotation of the wheel throws the oil up
into pockets, from whence it is conducted
through pipes to the crank-case. The angle ot
the pipes is such that even on extreme grades
there is sufficient drop to insure a flow of oil.
A depression M is found in the crank case be-
neath each connecting rod, in order to limit

The Automobile Handbook

the amount of oil carried in the crankcase, and
also to insure an even level of oil withio the

Drillixq Oil Passages in the Crank Shaft.
Figs. 2:15 and 236 show two different tnethodc
of drilling the crankshaft to convey the oil to

The Automobile Handbook

503

the crankpins, and it will be noticed that the
oil holes discharge at the highest point of the
revolution, corresponding to the position of the
piston at the beginning of the power or firing
stroke. The supply is received by the main
bearings from the oil pump and the oil hole in
the shaft, coinciding with that from the oiler
has a little oil forced in each revolution and,
generating centrifugal force throws it rapidly
through the passages. The majority of modern
motors are equipped with splash lubrication
and have the connecting rods dip into the oil

Fig. 235

each revolution and splash it all over the inside
of the crankcase. Some types are equipped
with a scoop pointing in the direction of rota-
tion, at the lower end of a passage connecting
with the crank pin. The oil is sent into these
passages with considerable force, owing to
speed of rotation, thus assuring sufficient oil to
the connecting rod bearings.

This is worked to the ends of the bearing and
thrown off in the shape of a fine mist that pen-
etrates to every part of the crankcase. The oil
splashed onto the lower cylinder walls and not

The Automobile Handbook

carried up by the piston is caught in little
troughs, cast in the crankcase and drilled so
that the oil runs down to the main bearings.
In addition to the pipe from the oiler, the bet-
ter designs provide an oil wick, or an oil ring
or chain, all types carrying oil from a shallow
pocket corded in the bearing cap, the wick by
capillary attraction, and the. ring or chain, re-
volving with the shaft, their lower ends im-
mersed in the oil will carry up a considerable
quantity that will spread over the shaft. This

Fig. 236

oil ring system is used very successfully in elec-
tri('al machinery. With a splash lubrication it
is advisable to drain the crankcase at frequent
intervals, and also to put in a fresh supply of
oil.

Cai-e should be exercised to select heavy oil
for air-cooled engines or old engines, and a com-
paratively light oil for new cars.

Cylinder Oil Testing. There are really
two parts to the fire test, as it is called. One is
the test for flash point. This may be determined

,The Automobile Handbook 605

as follows: Take two pieces of glass of the
same size, and large enough to cover a small
glass beaker. In one of them cut a couple of
notches. These are for two purposes. One is
for the thermometer and the other for the flash
point determination. Insert a thermometer in
the beaker, filled with the oil under test. Place
the notched glass over this and the other piece
of glass over that, taking care to cover the
notch not in use. Now uncover this notch, note
the temperature, and apply a lighted match to
the opening. If nothing results, warm the oil
slowly over a flame to a higher temperature
and take another trial and reading. Continue
the test until upon the application of the
lighted match the oil vapor over the oil flashes.
The thermometer reading at that point gives
the flash point. The glass plates may now be
removed, and heating continued. The match is
applied at similar intervals, until finally the oil
burns, which will usually occur at about 50 de-
grees above the flash point.

An additional test is for precipitation at a
known temperature. This is also made in a
beaker. Two ounces is the usual amount. It
is heated to the desired temperature, at which
the oil may change color, but must not show a
precipitation. Still another good. oil test is the
evaporation test. This is the result of slow
heating, and the usual specification is that the
oil shall not lose over 5 per cent, of its volume
when heated to 150 degrees Fahr, for 12 hours.

506 The Automobile Handbook

Lubricating Syst^ims:

Full Force Feed, Oil is forced by pump
pressure to the main bearings and, by means
of drilled holes in crank webs, to crank pins and
through hollow connecting rods, or oil pipes
attached thereto, to the wrist pins. Oil returns
to sump, or reservoir, and is circulated again.

Force Feed. Oil is forced by pump pressure,
or the centrifugal force of the revolving fly-
wheel, to main bearings and through drilled
holes in crank webs to crank pins. The wrist
pins and cylinder are supplied by oil thrown
from connecting rods. The connecting rods do
not dip. Oil returns to sump, or reservoir, and
is circulated again.

Force Feed and Splash, .Oil is forced by
pump pressure, or the centrifugal force of the
revolving flywheel, to the main bearings and
through drilled holes in the crank webs, to crank
pins. The oil from the main bearings falls to
wells in the bottom of the crank case, or to ad-
justable troughs, into which the connecting rods
dip and splash oil to all parts of the engine.

Splash. A constant level is maintained in the
crank case by an overflow to the sump, or reser-
voir, below, whence the oil is circulated again.

Lubrication op Gears and Clutches. The
modern ball-])earing gear box requires but lit-
tle attention. Periodic filling with suitable lub-
ricants is sufficient. On chain-driven cars the
g(»ars and differential are usually exposed by
lifting one cover. On shaft-driven cars the

The Automobile Handbook 507

differential and rear axle system requires a cer-
tain amount of attention, as too much oil in the
differential is liable to leak through the axle
sleeve and hub, usually getting on the brake
drums. If this happens, the best thing to do is
to jack the wheel up and squirt gasoline on the
drum, slowly revolving it meanwhile. Manu-
facturers usually put a plug in the differential
case showing the proper height at which to keep
the oil level. The gear box should be kept a
little less than half full. If too much is put in,
the oil will be thrown out of the shaft and
bearing housings, but a little leakage does no
harm as there is always dust present and the
oil leaking will serve to fill the crevices and
make the case dust-tight. In regard to the
wheels, universal joints, clutch, and many lit-
tle places about the car, all need attention oc-
casionally as almost any motor car driver
knows.

The wheels should be cleaned and packed
with grease once or twice a season, universal
joints at intervals necessarily shorter. Latest
designs provide for their lubrication through
the shaft from the gear box. Earlier types are
best packed in grease and enclosed in a leather
boot. On many shaft-driven cars, where the
shaft runs through a sleeve, daily attention
should be given. The lack of a few drops of
oil may rob the car of 50 per cent of its power.
Multiple disc clutches use oil, or an oil and ker-
osene mixture, and the tendency seems to be

508 The Automobile Handbook

for the oil to gum. Their action when slipping
or dragging is sufficient indication as to when
they are in need of attention. Leather-faced
clutches will work much better when cleaned
with kerosene and given a dose of neatsfoot or
castor oil. The oil should be spread over the
surface of the leather by using a long knife
blade, or by running the motor for a few mo-
ments with the clutch released. When treating
the clutch leather this' way it is better to let
it stand over night if possible, and with the
emergency brake lever, or a block of wood
against the pedal hold the clutch disengaged.
A hand oil can with a long spout is almost in-
dispensable, and the starting crank, the steer-
ing pivots and connections, and the spark and
throttle connections, gear control and emer-
gency brake levers, clutch and brake pedals,
shafts and connections and the fan bearings
will all work much quieter and sweeter for a
few drops of oil regularly. It is the practice of
drivers to fill the oil can from the cylinder oil
supply and this practice is to be commended,
as many lower grade oils contain acids enough
to etch steel.

Gear Case and Rear Axle. It is a familiar
fact that the gear ease requires to be periodic-
ally emi)tied of oil, and the accumulated metal
grit washed out before fresh oil is supplied. The
same is true of the rear live axle casing, except
that the gears in the axle do not clash and
therc^fore do not wear out as fast as the change

The Automobile Handbook 509

speed gears. At least once in a season the oil
in the rear axle should be drained out, a liberal
supply of kerosene introduced, and the axle
jacked up while the engine is run to agitate the
oil and wash out the differential, etc.

Magnetic Gear Shift. The electric gear shift
may be said to consist of two units, the ** shift-
ing assembly," or group of magnets attached to
the transmission case, and the ** selector-switch,"
or push-button group, located on the top of the
steering column. The electrical current required
to energize the magnets is derived from a stor-
age battery, Fig. 237, ordinarily supplied as
part of the starting and lighting systems on all
cars.

The selector-switch is made up of a number
of buttons, one for each speed, and one for the
'* neutral" which has not electrical connection.
There is also a button for operating the horn.
These buttons are provided with arched, lami-
nated contacts of copper, backed up with a steel
spring and insulated from the button proper.
The top of the switch carries a locking-plate for
locking any button which may be depressed and
also carries an interlock, which makes it impos-
sible to press down more than one button at a
time. At the bottom is a hard rubber base,
which carries a copper contact for each button
and a contact common to all speeds. It also
serves as a base for the return spring provided
for each button.

Tke Automobile Handbook

The wiring, Pig. 238, consists of a lead paa
ing from each coil throu(^ a terminal block

Fig. 237
Action of the Magnetic Qear Shift

its particnlar speed button on the select
switch, while the other lead from the eoU
joined to a neutral wire directly through

The Automobile Handbook

511

terminal block to the battery, with a master-
switch intervening, while another wire from the
battery passes through the terminal block to the
contact of the selector-switch which is common
to all speeds. The current travels from one ter-
minal of the battery through the depressed push
button on the selector-switch, down and around
the coil selected, and then back to the other ter-
minal of the battery.

PUSH-BUTTONS ARE ^
MOUNTED UND6R
STEERING WHEEL

GEAR SHIFTING
MECHANISM

IS MOUNTED ON TOP OF TRANSMISSION CAS^

Fig. 238
Connections of the Magnetic Gear Shift

The Vulcan electric gear shift mechanism con-
sists of a case which is attached to the transmis-
sion housing. This case, in turn, carries the
magnets or solenoids. These in turn surround
the plungers on which the shifting forks which
move the sliding gears in the transmission are
mounted. In this case, also, is carried the oper-
ating mechanism by means of which the gears

512 The Automobile Handbook

are mechaxiically drawn to their neutral position
through a connection with the clutch pedal. The
case is divided into two compartments, the small-
er of which is a pocket in which the operating
mechanism for the neutralizing of the gears and
the operation of the master-switch is carried.
This compartment is entirely enclosed on the
bottom, and is not open to the transmission case.

The neutralizing mechanism consists of two
shafts on which cams are mounted. One of these
shafts carries a pawl which engages with a latch
on a rocker arm. Upon the opposite end of this
rocker arm shaft is mounted a lever through
which the connection with the clutch pedal is
made.

Assuming that all gears are in a neutral posi-
tion (that is, the sliding gears are not in mesh),
and it is desired to start, the first speed button
on the selector-switch is depressed, closing one
l)reak in the electric circuit. The operating
lever and the shaft on which it is mounted are
rotated and the master-switch is pulled into en-
gagement through its connection with the oper-
iii'mo; mechanism which engages the switch stem.
As llie gear flashes into mesh, and is within ^<{
inch from being *'home," the master-switch
siia])s out instantly, due to the action of the
master-switeh spring, thus breaking the electric
oireuit. The actual time of engagement during
wliieh current is being drawn from the battery
is less than 1/S of a second.

Being in first speed, and desiring to proceed

The Automobile Handbook 513

to another, the other speed button upon the se-
lector-switch may be depressed at the conveni-
ence of the driver. Then, when it is desired to
shift, the clutch is fully depressed as before.

As the neutralizing cams rotate toward the
center, they press against a boss on whichever
side the gear is in engagement. This mechanic-
ally pulls the shifter fork and gear with which
it is engaged back to neutral position, before the
next shift can be made. The electric circuit is
again made complete, the current flows from the
battery through the solenoid selected and the
proper gear immediately jumps into engage-
ment. This action is the same for all speeds
in the transmission.

Should it be desired to stop, the neutral but-
ton on the selector-switch is pressed. This action
throws any other button which may have been
depressed out of contact, that is, it automatically
raises any other button which may have been
depressed previously.

Any selection may be made, at any time, by
pressing any push button on the wheel. This
selection, however, does not necessarily influence
the changing of the gears in the transmission.
In fact, nothing happens until the master-switch
is closed by the pressing, all the way down, of
the clutch pedal.

In the operation of this device the clutch
pedal may be slipped or fully released without
any action taking place in the gear shift mech-
anism itself. This is due to the fact that the

514 The Automobile Handbook

operating lever is attached to the clutch pedal
by means of an operating rod provided with a
link mechanism, which allows the clutch pedal
to fully release the clutch before it starts to pull
on the operating lever.

Magnetic Transmissioa^ see Cha^ige Speed
Gears,

Magneto; see Ignition, Magneto.

ADMISSION PIPE

Fig. 239

Manifold, Inlet. The internal diameter of
the a(hnission or inlet-pipe leading from the
carbureter to the admission-valve chamber should
not exceed one-fourth the diameter of the motor
cylinder.

Til is limitation is necessary in order to pro-
diiet! as great a partial vacuum as. is possible in
1h(» admission-pipe. The carbureter should be
l)laee(l as close as possible to the admission-
valve chamber of the motor in order to secure

The Automobile Handbook

515

the best results. Short turns or bends in the
admission-pipe greatly increase the air-friction
in the pipe, and at high speeds greatly diminish
the volume of the charge drawn into the cylin-
der by the inductive or suction action of the
motor-piston. An admission-pipe with a side
inlet and short bends, for a two-cylinder motor,
is shown in Fig. 239. Such forms of construc-

Fig. 240

tion should be avoided whenever possible. Fig.
240 shows an admission-pipe of approved de-
sign, with long bends, for a two-cylinder motor.
The radius of curvature of the pipe on its cen-
ter line should not be less than twice the out-
side diameter of the pipe. If space allows, a
radius of three times the outside diameter of
the pipe will give better results than two diam-

516 The Automobile Handhook

The desire to prevent condensation of the
gasoline vapor in the inlet manifold has led
many designers to fasten the carburetor flange
directly to the cylinder casting at the point of
entrance to the inlet valve passages. Others
have either completely or partially water-jack-
eted the inlet manifold for its entire length. In
all cases, the distance between the carburetor
mixing chamber and the inlet valve port is
made as short as possible.

A troublesome condition on many cars is
that caused bv minute air leaks in the inlet
piping and connections. If carburetor adjust-
ment is difficult, squirt liquid gasoline on the
inlet connections with the engine running. Any
change in engine speed is a sure indication that
one or more air leaks exist.

Motor, Electric Vehicle. A well designed
motor for use in connection with a storage bat-
tery for automobile propulsion must be capable
of withstanding an overload of over 100 per
cent for at least thirty minutes at a time, or for
even a longer period, without unduly over-
heating. The motors used on electric automo-
])iles are usually series-wound, as this type of
wiiidinof has been found to give the most satis-
factory results in general use.

There are three types of electric motors in
*rcncral use, these are :

Shunt-wound motors, in which the field-mag-
n(*ts are wound with a great many turns of

The Automobile Handbook 517

very small wire, the ends of which are directly
connected to the terminals of the commutator
brushes.

Series-wound motors, which have the field-
magnets wound with a few turns of very large
wire. One end of this wire i^ connected to
one commutator brush terminal. The other end
of the wire on the field-coils, and the other brush
terminal being connected with a battery or
other source of current.

Compound-wound motors are a combination
of the above motors, having the field-magnets
double-wound, that is with both shunt and
series-windings.

The armature of an electric motor is built up
of a number of disks of sheet iron, which are
separated from each other by a suitable coating
of varnish or by the use of thin sheets of paper
between the disks, this is to prevent what are
known as eddy currents, which are a source of
constant trouble if not eliminated.

The function of the commutator of an electric
motor is to receive the current from the battery
or other source of power^ by means of the
brushes, and transmit it to the windings or
coils upon the periphery of the armature.

The essential features of an electric motor
are as follows :

The brushes, which are located upon and
around the periphery of the commutator and
serve to transmit the current to the commutator
from the outside source of supply.

518 The Automobile Handbook

The Automobile Handbook Sl9

The commutator or current distributor, and
laminated wrought iron armature.

The field-magnets and pole-pieces; the lat-
ter are usually an extension of the magnet core.

The magnet frame, usually of. cast steel.

Figure 241 shows a form of series-wound
electric motor of the style most commonly used
for automobile work. The motor is of the four-
pole type, having its field-coils arranged at
equi-distant points around the periphery or cir-
cumference of the armature. The armature
shaft is carried by ballbearings, with suitable
screw and clamp adjustment as shown. The
armature is of the slot-wound type and has a
commutator with self-adjusting carbon brushes.
The left-hand extension of the armature shaft
is fitted with a 'key and washer for the driving
gear or sprocket, while the right-hand end has
a pulley or brake wheel to use for stopping the
car under ordinary conditions of travel. The
magnet frame is of cast steel, and the magnet
cores and armature disks of laminated wrought
iron. The field-coils are machine-wound, and
the armature coils form-wound, while both are
thoroughly taped and waterproofed. The com-
mutator generally has the same number of sec-
tions as the armature has slots and is usually
of large diameter and wide contact face.

Electric Motor Troubles. Electric motor
troubles may be classed as follows: Open-
circuits, improper connections and short-cir-
cuits. . — %?-

520 The Autotnobile Handbook

An Open-circuit may be found at any one of
the following places:

Battery terminals. These may be badly cor-
roded or worked loose, sq as to form a poor or
improper electrical contact.

Controller. A connection may have worked
loose, or the spring contact-fingers are not mak-
ing good contacts.

The removable plug may be out or not mak-
ing a proper contact.

Brushes. One of the carbon brushes of th»'
motor may have fallen out, or the brush springs
may be too weak to insure a good contact.

The rev^Tsing switch may be halfway over.
thus leaving the batteries and motor on an
oi)en circuit.

All points of contact, such as terminals or
binding-posts, ])rush-holders, switches and cou-
trolh^r spring contact-fingers, should be bright
and clean so as to give a perfect metal-to-metal
contact.

The fact that the car will not start and the
anini('t(M' sliows no current indication is gener-
ally an indication of improper battery connec-
tions.

WluMi th(* diiVerent trays of the battery are
not pi'()])('rly connected together, short-circuits
will occui' between these sections and run down
or (\\liaiist the batteri<'S in a very short time.
All l)att(»ry terminals should be plainly marked
so that it is impossible to make wrong connec-
tions. If the trouble above stated occurs the

The Automobile Handbook 521

battery trays must b€| wrongly connected,
amongst themselves.

If the ammeter indicates a large current and
the motor refuses to turn, the trouble is what is
known as a short-circuit, or a path for the
current outside of the motor.

Lift one of the commutator brushes, and if
the amperage shown by the ammeter drops, or
perhaps disappears altogether, one of the field-
coils is short-circuited or there is a broken wire
touching some part of the metal of the car or
an exposed portion of another wire.

Electric Motors, Speed-Regulation op. The
speed and consequently the power of an electric
motor may be varied in three ways, as follows:

First, by introducing variable resistances in
the motor and battery circuit.

Second, by varying the voltage of the bat-
teries by different combination of the battery
trays.

Thirdly, by connecting the field-coils of the
motor; all in series, in series-parallel and all in
parallel. Various other combinations of the
above named methods may also be had.

Muffler, Exhaust. When the exhaust gases of
an explosive motor are allowed to pass out
through the exhaust pipe directly into the at-
mosphere, the sharp explosions rapidly suc-
ceeding each other are very annoying, and it
is for this reason that the device termed an
exhaust muffler is, or at least should be, used.

522

The Automobile Handbook

Various types of mufflers are in use, each no
doubt possessing its own particular merit. The
function of the muffler is to deaden the noise of
the escaping gases, and the general re(iuire-
nients of the device are as follows: (1) It must
be built strong enough to withstand the force
of any explosion liable to occur within it, due
to the escape of an unexploded charge, which
may take place in one of the engine cylinders.
(2) It must check the velocity of the escaping

Fig. 242

gases without causing too much back pressure
on tlie motor. (']) It must deaden the noise.
Tlic last two ro(iuirements may be attained by:
(a"* Birakinp: up the gases into a number of
tiM<' streams: (b) Allowing the gases to expand
and cool; (c) Reducing the pressure of the
^Mses, until tliey are as nearly as possible at
atni()splieri(! pressure.

The terminal or c^xhaust pressure ranges at
i'l'oin -10 to r)() ])()un(ls per S([. in. above atraos-
])lieri(r pressure, wliile the temperature will be
800 to 1100 doj?reesF.

The Automobile Handbook

523

Muffler Cut-Outs. Mufflers are generally
equipped with muffler cut-outs, which by-pass
the gas so that it exhausts direct into the at-
mosphere with its attendant noise. There are
three reasons why they are so equipped, namely :
to tell if the engine is exploding regularly ; to
clean the exhaust pipe ; to have it act as a safety
valve in case of explosions in the muffler. If the
power of the engine increases when the muffler
is cut out, it is a sure sign that the muffler is of
defective design or needs cleaning.

Muffler Cut-Out Valve. One form of cut-
out valve is shown in Fig. 243. It is inserted
in exhaust pipe P, by sawing a hole in its imder

Fig. 243
Muffler Cut-Out Valve

side. The cut-out valve housing clamps to the
pipe by a couple of V-clamps. The valve is
carried in a cylindrical compartment under the
exhaust pipe, and consists of a spring closed
poppet valve a little larger in diameter than the
internal diameter of the exhaust pipe. It opens
against the exhaust pressure to prevent leakage.

524 The Automobile Handbook

Care of Mufflers. From time to time, all
mufflers should be cleaned, because it will be
found that they will contain a considerable
amount of carbon deposists. These deposits not
only tend to increase the back pressure, but
they retain the heat of the exhaust, thus al-
lowing the gases to escape at a higher tempera-
ture than they should. A muffler should be
taken apart and cleaned once a year, or oftener
if there are any indications of loss of jwwer,
resultant from back pressure.

A frequent cause of damaged or broken muf-
flers is the practice of ignition testing employed
by some mechanics. In case of trouble with
either source of ignition, the car is run at a
rather high speed on the good system, and the
ignition switch is then quickly turned to the
faulty side. If no explosions result, the switch
is again changed. In the time during which no
explosions occurred in the engine, the unbumed
mixture was pumped back! into the muffler*
When the switch is thrown to the good side,
the first power stroke sends a flame into the
muffler with the result that an explosion occurs
there, usually damaging the muffler seriously.

Packing'. Packing or material for making
gas, or water-tight joints is of various kinds.
Asbestos packing comes in sheets, called asbes-
tos paper or board, in the form of woven cloth,
and also as string or rope. Rubber packing is
made in shoots, either plain or with alternate
layers of canvas and rubber. Some forms of

The Auiomobile Handbook 525

packing are known as Rubberbestos, and Vul-
cabestos, and are made of asbestos, impregnated
with rubber and afterwards vulcanized.

Picric Acid. Gasoline will absorb or take up
about 5 per cent of its weight of picric acid.
The addition of a small quantity of kerosene
will enable the gasoline to absorb about 10 per
cent of pircric acid.

Picric acid is only dangerous when fused, or
when in a highly compressed state.

An increase in motor eflSciency of about 20
per cent is claimed for the picric-gasoline mix-
ture.

About three-tenths of a pound of picric acid
is required for each gallon of gasoline. The
mixture should be allowed to stand for two
days, agitating occasionally* during this time,
then strain through two or three thicknesses
of very fine muslin before using.

It must be remembered that picric acid is an
etching ingredient, which is another way for
saying that it will destroy the cylinder walls.

The explosive force of picric acid is very
much overrated. If thrown upon a red hot
plate of iron, it simply burns with a smoky
flame, and striking a small quantity of it upon
an iron anvil will not explode it.

Piston Head Scraper. In most engines the
piston heads can be scraped clean of carbon
without removing the pistons from the cylinders,
by means of specially formed scrapers intro-
duced through the opening over the valves, or

526 The Automobile Handbook

through the spark plug holes when the latter
are horizontal. The form and size of scraper
will depend on the particular engine, but al-
most any suitable form may be made from 5-16-
inch steel tubing about 12 inches long hav-
ing the ends hammered fiat, and turned over at
right angles in a vise. The ends are then
filed straight, and sharp, and the shank of the
scraj)er may be bent to right or left, if neces-
sary, or left straight. Frequently two scrapers
will be needed in order to use both right and
left hand bends. The advantage of tubing for
this purpose is that no blacksmith work is nec-
essary.

Platinum. The contact points of the vibrator
of an induction coil should always be of plati-
num. German silver or any other metal spoils
thi' quickness of the break on account of the
jiTc^ater tendency of the contact-points to car-
bonize, Avhen of any other metal than platinum.
Spark plug points should also be of platinum
or iridio-platinum, which is better yet, as it is
nsorci capable of withstanding the intense heat
in llie combustion chamber than the platinum
its(4f. Any otluT metal than platinum (except
gold) will turn green or black if tested with
nitric acid.

Polarity. To ascertain the polarity of the
terminals of a storage battery or light circuit,
])lacc the ends of the wires on the opposite ends
of a small piece of moistened litmus paper. The

The AtUomobile Handbook " 527

rire on the side of the paper which has turned
ed is the negative pole of the battery.

Porcelain. Porcelain tubes used for the in-
ulation of the center rod of a spark plug have
ligher insulative properties than lava or mica,
►ut on account of the liability of the porcelain
o break from too sudden change of tempera-
ure, it is not as reliable as other forms of in-
ulating material.

Poimding — Causes of. The most obvious
ause of pounding is that of a spark advanced
00 far. This, however, nearly always occurs
ipon hills, in deep sand or mud, or elsewhere,
whenever the engine is laboring very hard. In
he case of too far advanced spark, manipula-
ion of the spark would only make the pound
7orse than ever. So, too, if the spark was nor-
aally set too far advanced, it would pound
fiore at high speeds than at slow, just the re-
erse of the actual case.

Preignition causes pounding, and is itself
aused by overheated piston or cylinder walls,
irlowing points or deposits of carbon within
he cylinder, as well as faulty or uncertain igni-
ion also cause it. Leaks in the chamber are
ometimes the cause of pounding, so too, are
3()seness of parts. Among the latter may be
ited: connecting rod bearings, main bearings,
30se flywheel, cracked flywheel, other lost mo-
ion. Beyond these things, the only other cause
f pounding is that of some moving part which
trikes as it rotates.

528 The Automobile Handbook

Preignition — Causes of. If the inside sur-
faces of the combustion chamber are free from
sharp corners or projections formed in casting,
preignition is probably due to the combined in-
rtuences of high compression, and carbon or dirt
on the piston head. Next to the exhaust valve
itself the piston head is the hottest part of the
engine, since it cannot be water cooled. For
this reason it is much more important to keep
the piston head clean than the other surfaces
exposed to flame, and this is best accomplished.
first, by the use of a good non-carbonizing oil,
and, second, by thoroughly screening the air
intake. If preignition is troublesome it will
pay to fit a dust screen underneath the engine
in case none is already provided, since what-
ever (lust touches the piston head will be held
th(Te by the oil, and will be fully as eflPective in
causing preignition as the same amount of
car])()n. The intake itself should draw air
through at least one, and preferably two or
morc^ fine wire gauze screens of suflBeiently large
ar(ui to permit the air to pass through them
slowly. Those screens should be removable, and
should be inspected, and cleaned with gasoline
and a tootli])nish as often as may be neeessarj'.
It will ])e found that the fitting of a suitable
(lust scHM^n l)en(vith will make an immense dif-
f(M*ciicc in the amount of cleaning, which the
gauzf^ screens rofjuire. In the manufacture of
high classed motor cars the greatest care is
tak(Mi in scraping the walls and dome of the eyl-

The Automobile He ibook 529

inder castings forming the combustion space,
the aim being to remove every projection that
might cause a pre-ignition point as also to re-
move every burr, or rough spot to which for-
eign matter would adhere. The lubrication
system of a car is a most important factor in the
elimination of preignition due to the proper
amount of oil being fed to the cylinders at all
times.

Pump, Water. The circulating pump is
used in the belief that it affords a means for
regulating the temperature of the jacket water
supply, which would not always be the case
with a thermal-syphon system. Such is not the
case, as the pump, being driven direct from the
motor, operates at a speed which varies with
the motor speed. On starting the motor, it
pumps cold water into the jacket. It pumps
slowly at slow speeds, although the motor may
be taking a full charge and heating rapidly. It
pumps fast at high speeds, although the wind
pressure and its consequent cooling effect may
be very great. If a circulating pump could be
used in connection with a device to control the
regulation of the motor temperature, the results
would be more satisfactory.

Eotary pumps used in the water circulating
system of gasoline automobile motors are of two
forms, centrifugal and positive, or force-feed.
A positive or force-feed rotary pump is shown
in Figure 244. An annular ring around the
pump shaft carries two blades, one of which is

530

The Automobile Handbook

hinged to, and the other attached directly to

Fig. 244

the pump shaft. The outer ends of the blades
are supported in the periphery of the annular
ring, and rotate eccentrically with it. The
pump shaft is concentric with the pump cham-
ber, but the annular ring is located eccentrically
around the shaft, which drives it by means of
the fixed blade on the shaft.

Fig. 245 illustrates another form of posi-
tive-feed rotary pump, in which the pump shaft
is eccentrically located in the pump chamber.
A short cylinder which forms a part or portion
of the piuiip shaft, carries two blades in a slot-
t(jd opening parallel to, and coincident with the
axis of the pump shaft. Those blades are kept
in contact with the interior periphery of the
piuiip chamber by means of coil springs, located
betwc^en the blades as shown. Eotation of the
cylinder in the pump chamber causes a sliding

The Auto\ bile handbook

reciprocating action af the blades, due to

Fig. 245

pressure of the coil springs between their
er ends.

^umps — Centrifugal. In this type of pump

height of lift is governed by the tangential

3e. Owing to this fact centrifugal pumps for

on automobiles may be made of aluminum

the housing, as it is both light and strong,

y able to withstand the pressure, there being

rubbing surfaces. The wheel, however,

uld be made of phosphor bronze of a good

de. In these pumps the suction inlet is

ally at one side surrounding the axis, see

. 246. The pump should be geared to a speed

ligh if not higher than the crankshaft speed.

J minimum peripheral velocity of the pump

3el should be 500 feet per minute. For au-

lobile service the general rule is to have a

532

The Automobile Handitook

three vane wheel, and the cwving is away from
the direction of rotation.

Pumps, Water Circolatug. If steam ia seen
coming from the relief, or outlet of the water

Fip. 246
Scetion of a Centrifugiil Wnter Tump, Showing
of Water ut the Sid,: Ar.miiil the Shaft

firciilatinp system, look for a blockage of the
eircnlaticm, or failure of the pump.

If some of the radiator tiiln's are cool and
Htlicrs arc hot, look to the pump.

To tfst the pnmp before startinp:, nm the
motor for a few minutes. Then asccrtaiD how

The Aviomobile^ Handbook 533

long it takes before the top radiator tubes are
thoroughly hot. If the heat of the pipes is uni-
form the circulation is all right.

Rheostat. A rheostat is a device for regulat-
ing the flow of current in a closed electrical
circuit, by introducing a series of graduated
resistances into the circuit.

Rubber, India. All articles made of com-
mercial rubber should be kept from contact
with oil, kerosene, gasoline or grease if they
are to be kept in good condition. Vulcanized
rubber should not be exposed to a temperature
of more than 130 degrees, Fahrenheit. Com-
mercial or vulcanized rubber contains not to ex-
ceed 30 to 35 per cent of pure India rubber, as
its stretching quality, stickiness and rapid dete-
rioration under the action of light and air make
its sole use undesirable.

EuBBER Cement, How to Make. Marine glue,
so-called, is an excellent cement. This consistR
of one pound of caoutchouc to one gallon of coal
tar naphtha, and twenty pounds of shellac.
Heat gently and pour on metal plates to solidify.
When needed, melt. By using more naphtha,
this is made thinner so as to stay liquid. The
sulphur in this is in the caoutchouc, but if found
insufficient in any one case, more sulphur may
be added to the cement in the powdered form,
when making it up, or if necessary, when re-
melting.

Another excellent cement is gutta-percha

534 The AutoHiubdc Handbook

eciiient. The composition of this is two part>
of gutta-percha to one part of common pitcii
It is melted together, and well-stirred in the
melting, the stirring being fully as important
as the materials. When thoroughly melted aiM
stirred, it is ])Oured into cold water. This mak<'s
it into a hard brittle substance, which softens
at a low temperature, and at 100 degrees is a
thin fluid. Like the former recipe, this carries
its oAvn sulphur in the gutta-percha, but if mon'
is neeessary, it can be added as a powder. lu
til is ease, it is not advisable to add the sulphur
(luring the remelting process, but it should be
put in while making up a batch of the cement.

As a rule, as little cement should be us(h1 as
is i)()ssibl(^ to make a good job. Moreover, all
(Moment should be giv(*n plenty of time to dry.
Knl)])er surfaces to be united should be thor-
oughly eleMn(Ml. either with naphtha or with a
lliiii (MMiient. When the latter is us(»d, it is
brushed over the surface very lightly, using a
fine brush, and then the surfaces are heated
ircntly. This helps the whole operation, because
it both softens th(^ rubber, and evaporates the
solvnit. wliieli is tlien unnecessary to complete
llic o]><'rn1ion. hnviiig scTved its usefulness.

In addition to 1h(* various substances men-
tions 1 bd'orc For ('(Mnents. it is very often neees-
sni'v to linvc tlie ccnnMit dry very rapidly, Tr
these r.Mses. sp(M*i[i(» (Iricrs are added,. and may
usnnlly bt* nddcd to nny cement at will, tho
f|unntity nddctl Ix'ing mivisured only by the re-

I'he Automobile Handbook 535

quired speed in drying. Then there are eases
where certain degrees of tenacity are required.
For these, other gums are added, as rosin, mas-
tic, gumlac, etc. These, however, should be
used only when needed, and much discretion
should be used in adding them to an already
very satisfactory cement.

Running Grear. A complete running gear in-
cludes the frame, springs, wheels, motor, speed-
change-gear, axles and the machinery of the
car except the body. The French word, chassis,
is sometimes used to designate a running gear,

Secondary Current. The current which takes
its rise in the fine wire of the induction coil, and
which flows through the wire to the spark plug,
is induced in the fine wire by the sudden rever-
sal of the magnetism of the iron core.

This change of magnetism is caused by the
sudden interruption of the primary current.

Self-firing, Causes of. If the motor should
continue to run after the switch has been
opened, it is due to an insufficient supply of
lubricating oil, causing the motor to overheat,
or to the presence of soot or some projection in
the combustion chamber becoming incandes-
cent. It may also be due to lack of water or
to the water circulation working poorly, caus-
ing the motor to overheat.

Shaft Drive. The principal advantages which
may be advanced for the shaft drive are, absence
of noise, convenience with which all the parts
may be housed in oil and protection from

536

The Atitomobile Handbook

dust. It is especially adapted for use upon cars
carrying their engines in front, with the crank-
shafts parallel with the length of the car, as the
direction of the power shaft does not have to
,be changed until the rear axle is reached, and
as the power must also pass through one set of
bevel gears, it is more efficient.

The principal disadvantages of the shaft
drive are that it is difficult to repair ; it is some-

Fig. 247

Pouring Parson's Metal

what more complicated; it has considerable
end-thrust and it is claimed that it is harder on
the tires.

Shop Kinks. To reline a journal box with
Parson's white brass, proceed as follows: Pre-
pare a r('as()na])ly smooth cast iron plate A, Fig.
247, which is bored to receive a vertical man-
drel B a])out 8/16 inch smaller in diameter than
the finishing bore of the box. An annular brass
ring C, about ViJ i^cli wide, and whose in-

The Automobile Hcmdbook

537

side diameter is about % inch, smaller than
the outside diameter of the end flange D
of the box to be lined, is then located on
the iron plate concentrically with the man-
drel, and secured by means of pins or other-
wise. This ring serves as a support for the
box itself, and in the process of pouring, the
space between the ring and mandrel is filled
with white brass which is afterward turned off.
Any imperfect metal which may be poured will

Fig. 248

find its way either into this space or into the
space above the box, leaving the lining of the
box itself perfectly sound. The box itself is
assumed to have been suitably counterbored
and recessed to hold the lining as shown in the
sketches E and F, Fig. 248. It is preferable to
use the arrangement shown at F and allow the
lining to extend beyond the ends of the box, and
form the outer surface of the flanges. In this
case the diameter of the flange formed by the
lining will be the inside diameter of the sup-

538 The Automobile Handbook

porting ring, which will be slightly smaller than
the diameter of the flange of the box itself.

The halves of the box — if it is split — are
wired together and the box and the mandrel are
heated by torches and assembled as shown in
the sketch. A second ring — ^not shown — simi-
lar to the supporting ring is placed on the top
of the box, and all the cracks are luted with
moist fire clay. Meanwhile, the white brass
has been melted in a kettle to a fairly high
heat somewhat higher than the pouring temper-
ature. While it is being melted, it is kept cov-
ered by about 1 inch of powdered charcoal,
whicli excludes the air. When the maximum
temperature is reached, the charcoal is quickly
skimmed oiY and a handful or two of powdered
salammoniac is thrown on. The salammoniae
is immediately volatilized and forms a heavy,
tliou^ih colorh'ss gas which shuts off the air
from tli(» surface of the metal and causes it to
stay ])i'iirht. The pouring is then done with all
I)ossib](» liaste, and on cooling the metal will be
foimd p(M-r('c11y homogeneous and solid. If the
box is s[)lit tlio lining can be condensed by pen-
inii'. If the box is solid, the lining is simply
bored to llic i)r()])(T size.

'J'o JiKs-roKK A Sagged Frame. A frame which
is sauLicd to the extent of permanent deforma-
tion can ])e restored so as to approximate its
ori«iinaI slin[)(\ hy heating it in a charcoal fire
with an air blast. To do this properly, it wil^
most likely be necessary to cut out the rivets.

(

The Automobile Handbook 539

so that the side members can be handled inde-
pendently. A good plan of procedure is to in-
close the bent portion of the frame in a section
of stovepipe of sufficient size in which the cha^r-.
coal fire is built. A length of 1-inch gas pipe,
closed at one end, and having 5/16-inch holes,
drilled at intervals of about 6 inches, is laid in
the bottom of the pipe and furnishes the air
supply from a bellows. When the charcoal fire
is well kindled, the frame is introduced upside
down, and is supported at the ends. The fire is
then conceintrated on the bent portion, and as
the frame becomes hot it will straighten itseJf.
It must be watched carefully and the air blast
stopped as soon as the frame is seen to be
straight. Most of the frames used in American
cars are ordinary carbon steel, and require no
special treatment. It will be well, however, on
stopping the air blast to shift the stove pipe to
a cooler portion of the frame, to permit the
part which has been straightened to cool as
quickly as exposure to the air will permit. A
frame which has been sagged and straightened
in this manner will require to be trussed to pre-
vent recurrence of the trouble. As conditions
vary so much the best rule to follow is to ob-
serve the truss arrangement on some similar
car. The struts should be about 4 or 5 inches
long, and should be loca4;ed at the spots where
the sagging has occurred. The truss rod itself
should be about I/2 inch in diameter, and drawn
taut by a tumbuckle, which may be finally

640

The Automobile Handbook

tightened when the chassis has been assemble
Spanish Windlass. The old fashioned Spa
ish windlass, in Fig. 249, may be occasional
. employed w^here no other hoist is available,
is extremely handy in setting, and lining i
motors, transmissions and rear axles. It co
sists of a round bar or piece of pipe, a piece
"•ope, and a lever such as a small crowbar

Fig. 249
Spanish Windlass

jnek-handlo; all of which are quite common
the ordinary repair shop. The round bar
laid across the side members of the frame, 1
rope is made fast to the object to be hoisted
loo]) of it is wound around the bar as sho\
and till* lever inserted in the end of the lo
Allhou^h this is as old as the hills, it is not i
common to see a man lying on his back, ii

The Automobile Handbook 541

ost uncomfortable position, holding a heavy
ansmissiori case up into place while another is
ying to locate the bolt holes, and adjust the
lers ; whereas, if this makeshift windlass were
aployed, one man could raise and set the gear-
►X with much less trouble.
Straightening Spindles. In Pig. 250 a tool

shown which is used in a local repair shop,
r straightening spindles. The tool, which is

heavy construction, is placed in a vise; the

Fig. 250
Tool for Straightening Spindles

indie is heated to a red heat, the ends cooled
I with water, and placed between the centers,

illustrated. A lever is then placed between
e bent portion of the spindle and the shank

the tool, so that when pressure is brought to
ar on it, the spindle arm may be brought
ck into its normal position.
Cleaning Aluminum. Aluminum, such as
ed for foot-boards of cars, may be cleaned by
ing hyposulphate of soda, as this substance is
solvent of aluminum tarnish. The dirty sur-

542 The Automobile Handbook

The Automobile Handbook 643

ice should be wa,she.d with a strong solution
: the hyposulphate ; then rinse the surface with
ater and drj^

Care op Tire Pump Leather. The proper
bricant for the cupped leather washer of the
re pump piston is vaseline. Oil is too thin
id it tends to work into the rubber hose, and
^en into the tire itself if too much is used. Vas-
ine, on the other hand, clings to the leather
id lasts a considerable time. If the leather
icomes dry it does not hold air well, and pump-
g to high pressure becomes impossible, while
e labor of pumping even to low pressure is
•eatly increg,sed.

Replacing Broken Ball. When replacing a
'oken ball in a ball bearing it is better to re-
5W the whole set, unless the new ball can be
refully gauged to be of the same size as the
hers. If this is not attended to, the new ball,
iving to bear more than its share of the
eight, quickly succumbs. The greatest care
ould be taken, of course, to use grease free
om grit, and to clean the balls and bearings
;fore they are replaced.

Cleaning Tops. Tops may be cleaned by us-
g gasoline, a little ivory soap and a brush.
)metimes, however, when cleaning with gaso-
le the water-proofing quality of the materials
ay be destroyed. This can be restored by an
^plication of paraffine. Dissolve the paraffine
ith gasoline and apply with a clean brush, the
Lsoline will carry the paraffine into the fabric

544 The Automobile Handbook

and will evaporate, leaving the paraffine in the
fabric.

Useful Hints. At A, Fig. 251, is shown a
simple tool found to be universally useful for
wedging off magneto driving pinions, and other
small members fitted to. coned shaft ends, with
or without key retention. This can be easily
made from a large file, or any piece of steel of
sufficient dimensions, depending upon the work
to which it would be applied. The opening in
the fork need not be more than three-quarters
inch for the average magneto, the tines about
two inches long, and three-eighths inch wide and
taper from nothing to about one-quarter inch
at the thickest part. Two of these are needed
and are placed back of the gear, the tapered
portion of one piece resting on that of the
other, as shown. To remove the gear the ends
are driven in toward the centre at the same
time. This exerts a lifting effort, due to the
wedge action of the tools immediately back of
the pinion. The advantage of this method is
that the shaft on which the gear is mounted is
not snbjiM'ted to any side strains, such as would
result if att(»mpts were made to drive off the
gear by holding an S wrench back of the gear
and driving against it with a hammer. When
removing worn sprockets from the counter
shaft in order to replace them with new ones,
trouble may bo experienced in loosening the
nut especially if the rear wheels have been re-
moved. In such cases the chain may be utilized

The Automobile Handbook 545

to hold the sprocket in the manner shown at
B, Fig. 251, by anchoring it to the axle with
an S hook made of three-eighths inch cold rolled
steel rod The sprocket will be fimdy held and
the nut removed without difSeulty.

Although some grades of rubber hose are bet-
ter than others, unless properly cared for even
the best will deteriorate rapidly. Among the
factors which make for rapid wear are careless
stowage and abuse. The hose is left on the
wash stand, cars are run over it, and when it
has served its purpose, it is thrown in a heap
and oil and grease accumulations soon work
havoc with the rubber walls. A good ruJc to
follow is to have a place for everything and
everything in its place. It is not unusual to
see a coil of hose carefully hung upon a nail,
as shown at C, each coil having a sharp
''kink" in it, both top and bottom, as indicated.
This sharp bend tends to break the fabric walls,
and the hose soon leaks. The proper way of
hanging a hose is to use five or six wooden pegs
arranged around an arc of a circle, as shown.
Under these conditions the coils take a grad-
ual curve, and do not assume a sharp angle as
when but a single point of support is utilized.
If the hose is one of some length a reel should
be used.

Often when fitting bushings and parts, and
in general operations where reamers are used
it is found that the tool will be just a trifle
andersize, or that it is desirable to have the

546 The Automobile Handbook

reamed hole just a little oversize. In such cases
a simple expedient, as shown at D, Fig 251, will
be found valuable. A small sheet of brass, or
zinc is rolled in such a manner that it will fit
between two of the cutting edges of the reamer.
If the reamer is inserted with the roll of metal
in place it will be evident that the reamer will
be forced a trifle from the centre of the bore
and the cutting edges of the reamer opposite
the inserted metal roll will remove the metal.
Very fine cuts should be taken, and the metal
roll placed between different cutting teeth each
time that the tool is used. In tapping out nuts
it is often desirable to have the thread a little
deeper than the standard, or to have the nut a
loose fit on the bolt, as is sometimes necsesary
when trying to place a machine screw nut on a
'jariiage bolt. In this case a similar roll of
metal may be placed between the cutting edges
of the tap, as shown at E, Fig. 251.

SotjDer. Silver solders are generally used for
very fine work. They are very fusible, and
non-corrosive. Hard spelter is used for steel
and iron work, and soft spelter for brass work.

When copper is soldered to iron or zinc, resin
should be used, or if chloride of zinc is used for
a flux, the joint should be washed afterwards
to remove the acid. Un-annealed wires should
b(^ soldered at as low a temperature as possible.
Solder is always an alloy of other metals. It
must not only bo more fusible than the metal, or
metals to be joined, but it must have some chem-

The Automobile Handbook 547

ical affinity for them. Different kinds of solder
are therefore employed for different purposes.
It is called either hard or soft, according to its
fusing point.

Solders and spelters for use with different
metals, and their proportional parts by weight
are
Solder for:

Electrician's use — 1 — ^Tin, 1 — ^Lead.

Gold— 24^Gold, 2— Silver, 1— Copper.

Patinum — 1— Copper, 3 — Silver.

Plumber's— Hard— 1— Lead, 2— Tin. Soft—
3— Lead, 1— Tin.

Silver — ^Hard — 1 — Copper, 4 — Silver. Soft—
1 — ^Brass, 2 — Silver.

Tin— Hard— 2— Tin, 1— Lead. Soft— 1— Tin,
1 — Lead.
Spelter for:

Fine brass work — 8 — Copper, 8 — ^Zinc, 1—
Silver.

Common brass — 1 — Copper, 1— Zinc.

Cast iron — 4 — Copper, 3 — Zinc.

Steel — 3 — Copper, 1 — Zinc.

Wrought iron — 2 — Copper, 1 — ^Zinc.

Fluxes for Soldering. Some good fluxes for
soldering purposes are:

Iron or ateel .Borax or sal-ammoniac.

Tinned iron Resin or chloride of zinc.

Copper to Iron Resin.

Iron to zinc Chloride of zinc*

Galvanized Iron Mutton tallow or resin.

Copper or brass Sal-ammoniac or chloride of zinc.

Load Mutton tallow.

Block tin Resin or sweet oil.

♦Chloride of zinc Is simply zinc dissolved in hydrochloric
(muriatic) acid, until the acid Is znt or killed.

548 The Automobile Handbook

Scratched Cylinder. The cylinder may be
temporarily fixed by taking it to a first-clasB
tinsmith and having the scratches filled with sil-
ver solder. The soldered places must be then
carefully scraped flush with the bore of the cyl-
inder. The best way is to have the cylinder re-
bored and the piston-rings re-turned.

If the scratches are not too deep the cylinder
can be rebored, and a new set of piston-rings
made to fit the new bore. The limit to such an
increase in bore is about one-sixteenth of an
inch.

If the damage to the cylinder walls has been
comparatively slight, due to the conditions
being recognized early, the engine should be
disassembled and the surfaces thoroughly
cleaned of any dirt or carbon. After reassem-
bling, the full amount of lubricating oil should
be put into the engine, and with the oil should
be mixed an amount of graphite, in either the
amphorous or flake form, proportioned to the
kind being used and the body of the oil. Con-
tinued use of graphite will tend to fill the
small scratches in the metal.

Garage — Cleaning Floors. A hot saturated
solution of common washing soda will do very
well. This can be made up in quantities and
stored against future use. If this method is
used, be sure to reheat it before using, the boil-
ing point being about right. Since that will be
too hot to apply with the hands, use any old
broom or brush to "slosh" it around on the

The Automobile Handbook 549-

floor. An equally good, if not better, solution to
use for this purpose is trisulphate of sodium,
marketed by several chemical companies, and
sold at from four to five cents per pound at re-
tail. This can be used cold and will not injure
the most delicate hands; on the other hand, it
will clean them very thoroughly, so that users
of this solution use it for the hands as well as
for the floors. This is strong, however, and
may be used to remove paint.

Protection From Fire. The recommenda-
tions of the National Fire Protection Associa-
tion pertaining to garages and their operation
are as follows : No dynamo or gas engine should
be permitted where gasoline is stored or han-
dled; all exposed lights should be eliminated;
cleaning of acetylene lamps and removal or re-
newing of carbide should be carried on outside
ol garage; the residue of acetylene lamps
should never be cast on the floor; machines
should have oil tanks emptied before being put
in the repair shop ; the use of extension electric
wires is condemned, as they may cause fire ; mo-
tor testing should be done outside, for sparks
might ignite the fumes of gasoline; storage
tanks should be filled from outside of garage;
all volatile oils should be stored in good, heavy
tanks under ground, as far away from the
building as possible; pipes for filling storage
tanks should not pass through the garage in
any way; a filling station should be twenty to
thirty feet from the entrance to the garage, and

550 The Automobile Handbook

tanks of cars filled from there if it is necessary
to fill them when the cars are inside of the gar-
age; furthermore, the station should be fire-
proof, and all cars should be brought to fhis
point for filling; smoking and carrying of
matches, or use thereof should be strictly pro-
hibited; floors should be kept free of oil drip-
pings, and pails of sand should be kept handy
in proximity to gasoline.

A garage of ordinary size should be equipped
with at least four or five chemical fire extin-
guishers, and these should be placed so that
they may be quickly reached by any one in ease
of emergency. The stream from such an extin-
guisher will smother a fire before it has done
much damage if the flame can be reached within
a minute or so of the time when it started.
The chemicals usually used will not harm the
finish of the car if the surfaces exposed are
immediately washed in the usual way. Slight
marring is of course preferable to destruction.

Spark Plugs. The trouble with motors mis-
firing, is generally due to dirty spark plugs.
This is caused by using too much cylinder oil,
which, when subjected to the intense heat in the
cylinder, turns to carbon. This carbon depos-
its on the insulated porcelain and the body of
the plug, and instead of the current jumping
from the point in the body to the point in the
porcelain and making a spark, it follows the
easiest path, which is the carbon, and does not
make a spark at the plug points at all. When

The Automobile Handbook

551

this occurs the motor will misfire. The first thing
to do when a motor misfires is to test the spark
plug. Turn the motor until the battery eirenit
is closed. Unscrew the spark plug from the mo-
tor, then reconnect the wire to it just the same
as it was before. Lay the metal part of the
plug body on the flywheel or some other un-

A — Platinum point.

B— Thread.

C— Plug body.

D — Bushing.

E — Insulated terminal.

fig. 252

F — Porcelain bushing.
G — Expansion spring.
H — Asbestos washer.
J— Lock nuts.
K — Assembly nut.

painted part of the motor, being careful that
the metal part of the plug body only touches
the motor and that the porcelain part is clear.
If the spark jumps in short jerks between the
inner end of the porcelain and the interior of
the plug body it is sooted, and needs cleaning.

552

The Automobile Handbook

If it jumps at the points as it should do, tl
trouhle is elsewhere; probably at the batter
loose connecting wires, or the vibrator of tl
coil is not properly adjnsted.

SPARK PLUGS

Fig. ZU

To clean a spark plug properly use a 50 pi

cent solution of hydrochloric (muriatic) aei

washing the points of the plug with a too'

brush, occasionally dipping the plug into tl

Fig. 254

acid. After cleaning the spark ping in tl
manner, rinse it in water.

Spakk Pli gs — Construction of. Two spa
plugs are shown in Figure 252, which, while d
fering radically in their construction, effect t

The Automobile Handbook 553

same purpose, that of producing a spark or arc
in the eombustioa chamber of the motor. The
accompanying table and reference to Figure
252, will fully explain the construction of the
spark plugs.

Cross-sections of four different forms of
spark plugs arc shown in Figure 253. AH are
constructed with a view to make the outside or
extraneous path caused by sooting, as long as

n^jlf--^---

SPARK PLUG

lip

Fig. 255

ble, so as to prevent if possible short-cir-
cuiting of the plug from this cause.

Figure 254 shows a form of spark plug in
which two extra air-spaces are provided, one
between the center rod or terminal and the
porcelain hushing and the other between the
porcelain bushing and the shell or body of the
plug.

The spark plug shown in Figure 255 has a
closed chamber around, and over the center in-
sulated rod or terminal ; this chamber is a part

554

The Automobile Handbook

of the body of the plug and forms the other te
minal of the plug. It acts as a small combu
tion chamber, and streams of fire are supx)08€
to be thrown from the small openings in tl
chamber, when the arc or spark occurs therei

Fig. 256

An exterior view of a form of spark plug i:
general use is shown in Figure 256.

Spark phi^rs of American manufacture ar
made with three different sizes of threads: One
half ineh pipe-size, the actual outside diamete
of which is .84 of an inch, with 14 threads »£

The Automobile Handbook 555

inch. Seven-eighths of an inch diameter, with
18 threads per inch, and .7 of an inch diameter,
with 17 threads per inch. The last named one
is the French, or Metric standard thread.

Specific Gravity. In the absence of a proper
instrument, the specific gravity of gasoline or
any other liquid may be obtained as follows :

Weigh a certain quantity of distilled water
at 4 degrees Centigrade, or 39 1/3 degrees Fah-
renheit.

Weigh the same quantity of gasoline or other
liquid under test.

Divide the weight of the liquid by the weight
of the water, and this will give the required
specific gravity of the liquid.

The specific gravities of various liquids are
as follows:

Alcohol at 15" C 0.794

Acid, nitric 1.217

Acid, sulphuric 1.841

Ether at 15" C 0.720

Naptha 0.848

Oil, linseed 0.94

Petroleum 0.878

Gasoline at 15" C 0.680 to 0.720

Water, sea, at 4° 1.026

Water, pure, at 4" 1.0

The specific gravity of the electrolyte used
in storage batteries is usually close to 1,250
under ordinary conditions. This figure will
reach 1.300 or 1.310 with a fully charged start-
ing and lighting battery, and may fall as low
as 1.100 with a battery that needs charging
badly.

The specific gravity of a storage battery
should be tested while the battery is being

556 The Automobile Handbook

charged or immediately after the charge has
been discontinued, never just after water has
been added.

To test the gravity, it is necessary to use a
hydrometer made and graduated for this work,
the instrument being preferably enclosed in a
tube fitted with a bulb and nozzle and called a
hydrometer syringe. With the filling caps re-
moved from each cell of the battery, the bulb is
compressed, the nozzle inserted into the cell and
enough liquid drawn up to float the hydrom-
eter. The marking on the hydrometer stem
at which the surface of the liquid remains is
the specific gravity of that cell. The gravity
should be nearly the same in all cells with a
good battery. The liquid should be returned
to the cell from which it was drawn.

Springs. The length and number of leaves
in the springs of motor cars of similar weight
and power vary, and without any reason for so
doing. The general use of pneumatic tires hides
many imperfections in this respect as well as
in others. Springs of insufficient strength are
a source of great danger, and frequent exami-
nation should be given to them. Springs are
not necessarily of insufficient strength because
they appear to be light. Short springs are not
desirable, as they are more liable to break than
a longer spring, the deflection per unit of
length being greater. Stiffness in short springs
is usually avoided by lightness, which is likely
to lead to breakage, especially when the hole

The Automobile Handbook

557

Fig. 257
Full Elliptic Spring, Scroll Ends

Fig. 258
Semi or Half-Elliptic Spring

Fig. 259
Three Quarter Elliptic Spring

Fig. 260
Fixed Cantilever Spring

Fig. 261
Three Quarter Floating Cantilever Spring

558 The Automobile Handbook

for the bolt through the center of the spring is
made larger than necessary.

Springs — Dimensions op. In calculating tho
dim elisions and elastic limit of springs for mo-
tor-car use, the elastic limit must be carefully
considered with regard to the dead, and maxi-
mum loads to be carried by the car. The dead
load is the weight of the car when at rest. Tho
maximum load is the greatest weight that can
possibly be carried with good spring action.
The springs to retain their elasticity should
have their ultimate strength far beyond their
maximum load capacity.

The old practice of fixing a uniform curva^
ture of the spring leaves frequently leads tc
breakages due to distortions set up at the
si)ring perch. This tendency is now aborted by
making the spring leaves in such a way that tht-
eurvature begins at points beyond the spring
pc^rch, so that the clamps when they are pulled
into tight relation do not straighten out the
])hites. It is still the custom to use a leather
])n(l on which to rest the springs, because
thereby th(^ coefficient of friction becomes that
of leather, and creeping tendencies are as a con-
seciucnce remoter There is also the question of
the c'cimber given to the respective spring plates.
If the phites ar(» all of the same thickness, they
should nil be curved to the same radius, for
tluMi the extreme fil)(»r strain would be equal in
all th(} plates for every alteration in camber in-

The Automobile Handbook 559

cidental to the service they are placed to per-
form.

Springs — Testing and Material. The life of
a spring is forecast by the maker thereof, al-
most independently of the quality of the mate-
rial. If the spring is limber, and it is so placed
as to indicate spring play, just at the point of
reversals of camber, the life will be shortened.
The superior grades of materials will stand this
abuse for a comparatively long time, but the
dynamic life of steel, like the life of every other
animated thing, is limited. Inferior materials,
advantageously situated, might last far longer
than the superior products working at a disad-
vantage. The initial camber to give a spring,
for a given static camber, is a problem for the
springmaker.

Fig. 262 shows three views of a given spring,
under the conditions as follows: The spring
under static load, indicating the static cam-
ber; straightened out under load; in reverse
camber, in a testing machine, to the limit before
permanent set.

It is worth while to study these three condi-
tions in relation to springs, because they have
to do with the life of the spring in service, and
the easy riding qualities of the car due to spring
action. It might be said in general that the
greater the difference between the initial and
the static camber, the more pronounced will be
the easy riding qualities, and it might be said
as well that the greater the initial camber, and

560

The Automobile Handbook

the groattii" the possible reverse eamber, the hvt-
ter will be the life of the springs, cspeeially if
we (iike into account that the spring action in
-serviee will be limited between the two points,
as represented by the initial camber on the oiH'
hand and the condition, which means that the
spring leaves will no more than straighten otit
in actual service. If the service conditions are
such as to eliminate any reversal of camber,

Fig. 262

tlien it may be said the factor of safety will be
I'l'pr'i'si-nfcd by the amount of the reverse cam-
biT ill a ti'sliiig machine before permanent set.
WinTN(;.-i — V.\Hy. OF, Springs shonld be exam-
innl (K-cjisiDTiJiIly. and while often overlooked.
Iliis sccniingly li^iHing matter has a direct bear-
iiiL' iii'on llic smciodi. easy nmning of the car.
Owiiij: 1o the fjH-t that the sprinfca are exposetl
t" the weaUicr. rust is very likely to occur at

The Automobile Handbook

561

this point, and to this unsuspected corrosion is
often due the pccasional ** squeak." Although
many cars iare provided with some means for
lubricating the friction, surfaces, many cars are
not so well provided for and when rust makes
its appearance along the joints there is a cry-
ing need for oil. This may be conveniently
applied by placing the jack between spring and
frame, and slightly opening the leaves or plates.

Fig. 263

The toggles and links should also have a little
oil occasionally and when about this work it is
well to examine the nuts of the clips. These
nuts are prone to work loose.

Sprockets. The circular instead of the linear
pitch is often erroneously used in calculating
the pitch diameter of a sprocket wheel. Refer-
ence to Figure 263 will illustrate the difference
between circular and linear pitch, and help to
demonstrate the case more clearly. The view at
the left of the drawing shows the circular pitch.

562 The Automobile Handbook

and the view at the right the linear pitch of a
gear or sprocket wheel respectively. If the cir-
cular pitch of the gear be one inch and the gear
has six teeth as shown, the pitch diameter will
be 6X0.3183, which gives 1.91 inches as the
pitch diameter. Let the linear pitch of tlie
sprocket be also one inch, and with six teeth as
before. In a sprocket having 6 teeth, the ra-
dius is ecpal to the linear pitch, as the figure is
conii)osed of six equilateral triangles, and the
pitch diameter of the sprocket wheel is conse-
quently 2 inches.

The pitch of the sprocket must, of course, be
the same as that of the chain to be used with
it. (.'liain pitches usually measure in even
iiicli(\s and common fractions. The type of
chain, whether roller, block or silent, must also
b(^ considcnnl. It is not safe to use mismated
cliains and sprockets.

Sprockets. Dimensions of. Table 11 gives the

pitch (lianict(»rs of sprockets for roller chain of
1 inch, 1V1 inch and IV2 inch pitch, with 7 to
2S t(M'th. The outside diameters may be found
by nddin^ the diameter of the roller to the pitch
dijiiiH'tj^r of \hv sprocket.

Si'KocKKT Cir.Mx LrBRiCATioN. The best lubri-
c;ni1 for sprocket chains is a constant puzzle.
rf oil is used it is absor])ed bv the dust which
st'tfh's on th(» chain. If tallow or other animal
^n'<'ast' is (Miiploycd it is pushed away from the
])carin^ surfaces, and the latter get dry. The
ideal ln])ricant would seem to be something be-

The Automobile Handbook

563

TABLE 11.

DIMENSIONS OP SPBOCKETS FOR ROLLER CHAIN.

1 Inch

1% Inch

Number of

Pitch.

' Pitch.

Pitch.

Teeth in

Sprocket.

Pitch Dia.

2.31

2.88

3.46

8 i

2.61

3.27

^ 3.92

2.92

3.65

4.38

3.24

4.04

4.85

3.54

4.44

5.33

3.86

4.83

5.79

4.18

5.22

6.27

4.50

5.62

6.75

4.81

6.01

7.22

5.12

6.41

7.69

5.76

6.41

8.64

6.39

7.99

9.59

'^2

7.03

8.79

10.55

7.66

9.58

11.49

8.31

iO.38

12.44

8.95

11.19

13.42

tween an oil and a grease, too thick to be drawn
ouf by absorption, yet soft enough and clinging
enough to stay in the rollers. This mission is
approximately fulfilled by a mineral grease,
such as non-fluid oil, or Keystone grease, which
are not affected by moderate changes of tem-
perature, and have the clinging quality which
animal greases lack. The makers of these
greases, however, do not recommend heating
them, and they cannot be introduced into the
links and rollers of the chains, except by ren-
dering them temporarily more fluid than they
are desired to be in service. A very good lubri-
cant for this purpose is made by dissolving Key-
stone grease in gear case oil, in amounts suffi-
cient to produce a viscous fluid at the boiling

564 The Automobile Handbook

point, which thickened when cold, and would
just barely flow. A fairly liberal quantity of
graphite was added, about half a cupful to three
quarts of dope, and the chains after cleaning
were boiled for half an hour or longer in the
mixture to enable it to penetrate thoroughly.

The Automobile Handbook 565

Starting and Lighting Systems.

Four principal types of engine starters have
een used; the air starter, the mechanical
:arter, the acetylene starter and the electric
:arter. Beginning with the production of 1916
ars, the electric starter is the only one found
s standard equipment.

Acetylene starters were used by many cars
1 1913. This form admits acetyleiie gas from
le lighting tank to the cylinder that is ready
) fire through a distributor valve. The passage
f an ignition spark caused by operating a but-
)n on the dash fires the gas and the force of
le explosion starts the engine.

Mechanical starters are found in many forms,
hey. consist of a mechanism through which the
river is enabled to turn the engine crankshaft
irough connections that lead to a handle or
jver that may be reached from the seat.

Compressed Air Starters. In a typical air-
ressure system the motor is operated with
Dmpressed air until regular explosions take
lace in the cylinders; the air supply is then
lut off and the motor takes up its regular
perations.

The parts of this self-starter are as follows
see Fig. 264) : 1, a high-pressure, four-cylin-
er air pump, for compressing air in a storage
ink; 2, a pipe for carrying air from pump to
borage tank; 3, a pipe which carries air from

The Automobile Handbook 567

tank to push valve on the dash ; 4, a pipe which
carries compressed air from the push valve to
the ** distributor" J 5, pipes through which air
is carried from the distributor to the various
cylinders ; 6, poppet valves — one in each of the
cylinders — ^by means of which compressed air
from the distributor is admitted to the cylinder
ready for the working stroke; 7, a pressure
gauge on the dash, which keeps the operator
informed of the amount of compressed air in
the storage tank ; and 8, a pump clutch, 'oper-
ated by a foot pedal, which throws the gears
of the air pump into mesh.

The air pump in this system is driven by a
silent drive chain from the water pump shaft,
and operates only when the gears are thrown
into mesh by pressing the pump clutch foot
pedal. It is a simple device for compressing
the air and delivers a steady flow to the storage
tank. A pressure of 50 lbs. in the tank will
start the motor under ordinary conditions, but
it is advisable to keep the pressure at about
150 lbs.

The storage tank is carried beneath the body
of the car and is tested for a pressure of 600
lbs. to the square inch.

The dash push valve opens the air line from
the storage tank to the distributor and simul-
taneously opens the cylinder valves so that air
coming from the distributor through the pipes
shown in Fig. 264 has ready access to the cyl-
inders. When the foot is removed from the

568 The Automobile Handbook

dash button, both the escapement valve and
the cylinder valves are closed automatically
and the compressed-air starter is shut off from
the motor.

The distributor sends charges of compressed
air into the cylinders ready for the workinir
stroke, in their order of firing. It is geared
to the pump and magneto shaft and positively
timed for feeding air.

This type of self-starter is also used for the
purpose of inflating tires by means of a special
shut-off valve and hose.

The principle of compressed-air starters is to
admit air under 50 to 150 lbs. pressure from a
trenerous reservoir directly to the motor cylin-
ders at the beginning of each expansion stroke.
This operates the motor without affecting the
mixture in the cylinders. When running under
air pressure the admission of the compressed
air at almost the moment of the spark operates
the same as an ignition, causing a rise of pres-
sure in the cylinder. After it has performed
its work this pressure is released by the ex-
ha list Vcilve in the same manner as the burned
erases arc released when the motor is running:
uih1(M' its own power.

The Automobile Handbook 569

Allis-Chalmers Equipment. The most com-
monly used type of AUis-Chalmers equipment
makes use of a combined Motor-dynamo, Fig.

AlUs-ChalmerB Motor- Dynamo. E, Commutator.

F, Brush Holder. G, Brush Connection. H,

Brusb Connection.
265, operating at six volts pressure for starting,
charging and lighting. In addition to the motor-
dynamo, the system includes the battery, a start-

570 The Automobile Handbook

ing switcli and a separately mounted combined
cut-out and regulator.

Pushing the starting switch connects the bat-
tery with the motor-dynamo, which then oper-
ates as a motor to crank the engine to which it
is meclianieally connected. The switch is then
released after the engine fires. The motor-
dynamo speeds up with the engine and, when
it reaches a certain predetermined speed, is auto-
matically connected to the battery and the light-
ing system by means of the cut-out. If the
lights are burning, part of the current is used
in lighting, the surplus going to charge the
])attory. When the engine slows down below the
charging speed, the cut-out opens the circuit be-
twiM'ii the generator and battery.

By removing the cover band, the commutator
may ho examined. Wlien in good condition it
will show a glaze and will be dark brown in
color. If the commutator appears dirty or
greasy it should be wiped oif with a clean cloft
fi'('o from lint, slightly moistened with oil.

Do not disturb the brushes so- long as the
mot<)i'-<renorator appears to be operating prop-
ei'ly. Tlicy should make good contact with the
coninnitntor and slide smoothly in the brush

lK)](h'l*S.

Tli(^ ])ni'poso of the combined cut-out and reg-
ulator is to connect the generator to the battery
wlien its voltage erpials that of the battery, ami
To inaintain a practically constant charging cur-
rent with tli(^ widely varying speeds of the en-

The Automobile Handbook 571

gine. It also disconnects the battery when the
motor-generator voltage falls below that of the
battery, preventing the battery from discharg-
ing.

The regulator-cutout consists of a compound
wound electromagnet with two armatures, one
of which serves as the cut-out while the other
regulates the charging current. The shunt reg-
ulator winding is always" connected across the
generator terminals. When the generator volt-
age is sufficient for charging, the electromagnet
attracts the armature, closing the circuit through
the series coil of the regulator of the battery.
The current flowing in the series coil then as-
sists the shunt coil to hold the contacts to-
gether. With an increase in generator speed,
the charging current will increase, strengthen-
ing the regulator electromagnet. At a certain
critical point the second armature will vibrate,
alternately cutting a resistance in and out of
the generator field circuit, which will reduce
the charging current by lowering the generated
voltage. When the generator speed, and conse-
quently the voltage, drops below charging value
the reverse battery current flowing in the series
winding neutralizes the shunt winding, releas-
ing the armature and thus opening the circuit
before the battery can discharge.

The internal connections and mechanism of
the regulator-cutout are shown in the diagram,
Fig. 266.

The regulator is provided with a fuse to pro-

572 The Automobile Handbook

The Automobile Handbook 573

tect the system from excessive charging current,
or an improper discharge through the starter,
in case the regulator should not function prop-
erly. This fuse has a capacity of 45 amperes
and carries the shunt field current as well as
the battery charging current. The fuse, which
is made of an especially hard alloy to withstand
the high temperature near the engine, should
always be replaced by one of the same make.
If several fuses are blown within a short time,
the regulator is probably out of order and
should be replaced. This fuse does not protect
the lighting and horn circuits.

To prove whether the motor-dynamo is charg-
ing the battery or not, remove the wire from
the ''BAT.4-" terminal of the regulator and
insert an ammeter between this terminal and
the wire, with the positive terminal of the meter
connected to the terminal of the regulator. With
the engine running at about 60 revolutions per
minute or higher, the meter should show a charg-
ing current of 10 to 18 amperes. If the meter
shows no current, the motor-dynamo is either
not developing any voltage or there is an open
circuit in the charging line. To determine
whether the motor-dynamo is developing any volt-
age, open the circuit at ammeter and then
remove the wire from the ^'F L D" terminal
of the regulator. With the engine still running
as above, there should be quite a flash on re-
moving the wire from the '^F L D" terminal of
the regulator. All these tests are to be'^a^de

574 The Automobile Handbook

with a good fuse in place on the regulator. If
no flash is obtained on removing the wire from
the *'F L D'' terminal, hold the wire on the fuse
clip for a few seconds and note whether there
is a flash on removing it. A flash here and none
from the '*F L D'' terminal indicates a fault in
the regulator. No flash from the fuse clip indi-
cates a fault in the motor-generator. It is as-
sumed here that the connections between the
regulator and the motor-dynamo have been ex-
amined and found correct and sound.

If the motor-dynamo develops its voltage but
still does not charge the battery, the fault is
either in the regulator or the auxiliary contact
of the starting switch. This can be located by
connecting up the ammeter again as before, and
with the engine still running hold a wire pumper
in the hands and first connect the "DYN+**
terminal of the regulator to the "BAT+" ter-
minal. If the battery now charges, the fault is
in the regulator. If no result is obtained, con-
nect *'BAT+'' terminal of the regulator to the
positive terminal of the battery. The charging
of the battery now would indicate that the fault
was in the starting switch.

The motor-d>Tiamo should not be run with the
charging circuit open, except for a minute or
two at a time in making tests and not at all at
Yevy high speeds, as it would damage both the
motor-dynamo and the regulator, and also the
lights if turned on. If it is necessary to operate
the- car with the battery removed or with the

The Automobile Handbook 575

battery circuit open in any way, so that !i lan-
not charge, the fuse must be removed from its
place on the regulator.

Auto-Lite Eqiupment. These systems con-
sist of separate unit dynamos and starting
motors operating with a six-volt pressure in all

Fig. 267

Auto-Lite Dynamo With Permanent Field Magnets

and Clutcb Goveruor

cases. The first models were of the permanent
magnet type, that is to say, the dynamo field
consisted of six powerful steel magnets without
the usual coils, Fig. 267. These magnets were
of the inverted U, or horseshoe, type, and under-
neath the areh thus formed was mounted an
electromagnetic cut-out which closes the charg-
ing circuit whenever the dynamo voltage is suffi-

376 The Automobile Handbook

<jiently high to charge the battery. This part of
the mechanism may be exposed by removing the
brush wires and taking out the plate that car-
ries the positive and negative dynamo terminals.
This permanent magnet dynamo is driven
from the engine by silent chain, but between
the chain sprocket and the dynamo armature
shaft is a form of slipping clutch governor con-
tained in the drum seen at the left hand end of
Fig. 267. The shell of this drum has its driving
connection to the shaft by means of two shoes
that are pressed outward by springs. Two
weights are carried at or near the ends of corre-
sponding arms inside of the drum, and when
the armature shaft has reached a certain pre-
determined speed the centrifugal action of the
weights overcomes the tension of .the springs and
the shoes release their hold on the shell. By
thus preventing an armature speed above the
desired maximum, the voltage and output of
the dynamo is held at a point suitable for bat-
tery charging.

A later form of Auto-Lite dynamo is shown
in P^ig. 268. This model retains the inverted U
form of field magnet cores, but around the top
of the magnet arch is placed a field coil housing
and in this housing is a shunt and a reversed
series field ^\anding. The shunt field winding
is attached between the brushes in the usual
way, and the entire dynamo output passes out
through the reversed series winding. This
series winding being placed in such a way that

The Automobile Handbook

577

it opposes the action of the shunt, dynamo out-
put above a certain point is made to overcome
the field magnetism to such an extent that the
amperage shows no further rise. The two
dynamo terminals are seen on the front of the
field housing and with this machine the electro-
magnetic eut-out is separately mounted, usually
on the dash of the car.

Auto-Lite Dynamo With Electromagnetic Fielda

■A third type of Auto-Lite dynamo is shown in
Fig. 269. This machine is fully enclosed and
has its fields placed above and below the arma-
ture. The field windings and regulation of out-
put by means of the reversed series coil is the

bin The Automobile Handbook

same as in the type just described. The brushes
and commutator may be exposed by removing
the plate A.

Bijur Equipment. These systems are made
in three distinct forms, two being six-volt sepa-
rate unit dynamo and -starting motor types.
while the third is a combined motor-dynamo op-
erating at twelve volts for both charging and
starting.

Fig. 269
Auto-Lite Pully Enclosed Dynamo.

One of the six-volt systems makes use of a
straight shunt-wound dynamo having a com-
hined regulator and cut-out mounted in an
aluniinuni housing on top of the dynamo ease.
Connfctcd in series with the shunt winding ia a
coil of high resistance wire which is automatic-
ally inserted in the shunt field circuit by the
regulator, this action keeping the voltage con-
stant. The regulator consists of an electro-
magtiet with its winding shunted acroBS the

The Automobile Handbook 579

brushes, so that current always flows around
the magnet when the dynamo runs, also the
regulator contacts which are connected to carry
the shunt field current around the resistance
coil when they are closed. As the dynamo volt-
age rises, the magnet pulls the armature against
the small spring and opens the contacts. The
shunt field current then flows through the re-
sistance and is so reduced that the field strength
and voltage immediately fall. The low voltage
reduces the strength of the electromagnet and
the spring again closes the contacts, allowing the
field current to avoid the resistance coil and
raise the voltage. The regulator contacts vibrate
this way at the rate of about 100 times a second
and this holds the voltage at a point determined
by the strength of the regulator spring or its
tension.

The cut-out is electromagnetic with two wind-
ings and is carried in the same case with the
regulator, this case being on top of the dynamo.
All connections between dynamo, regulator and
cut-out are made between the regulator housing
and dynamo case and are not exposed. Two
wires only come from the dynamo, one positive
and one negative.

The dynamo wires end in a brass plug on one
end of the regulator case. This plug may be
rotated in its socket so that it makes part of a
turn one way or the other. Turning this plug
as far toward the engine as it will go makes one
wire positive and the other negative, and turn-

580

The Automobile Handbook

ing it as far from the engine as it will go re-
verses this polarity. This reversal should be
made every 500 miles, being sure that the pliig
is turned as far as it will go so that it locks in
place. This action reverses the polarity of the
dynamo and prevents pitting of the contacts.

Blji

Fig, 270
f Wiring Diagram for Voltage Control System

After adjustments are made the regulator hos
is si'iih'il at the factory and the maker's instruc-
tioiLS say not to open it. The entire box may
l>e ri'Timved from the dynamo by unscrewing the
small milled iint on top, the connections between
till' c-asi'K liciiifr made with split pins. Lights
;i]iii sfarti'v will run from the battery while the
rrtrulatnr is returned to the makers for repairs.
\ iDinplete wiring diagram for this form of
Hijur apparatus is shown in Pig. 270.

The Automobile Handbook

In Fig. 271 is shown the apphcation of an-
other form of six-volt separate unit system.

This dynamo has no controller hox as has the
one just described, but the shunt field winding

582 The Automobile Handbook

is connected to an additional brush bearing on
the dynamo commutator. This brush is for the
purpose of limiting the dynamo amperage and
is so placed in relation to the main brushes that
the current passing into it, and thereby into the
shunt field, diminishes with increase of speed.
The normal tendency of the output to increase
with the speed of rotation is therefore counter-
acted and a safe maximum is maintained. This
is the form of regulation known as "third
brush."

The electromagnetic cut-out for this system
is mounted inside of the brush and commutator
end of the dynamo case. This end of the ma-
chine is closed by a removable brass band, and
through the openings left with this band re-
moved the working parts of the machine may be
inspected. Mounted on the outside of the dy-
namo case, and connected in series with the field
windings, is a small fuse which will blow out
whenever the current passing through the fields
becomes excessive. This fuse will protect the
dynamo in case of a broken circuit between
dynamo and battery or lamp lines.

Separate starting motors of Bijur make may
drive to the engine through an overrunning
clutch, through direct acting spur gears or by
means of a Bendix screw. With the Bendix
screw, a single contact starting switch is used
which sends the full battery current to the motor
when the switch is closed. With the spur gear
drive, the starter switch makes a preliminary

The Automobile Handbook 583

contact through a resistance coil and continued
movement of the switch pedal and plunger
closes the contacts that short circuit the resist-
ance and send the full battery current through
the motor. The same operation that meshes the
starting gears moves the switch plunger.

Bijur motor-dynamos operate at twelve volts
and have their output controlled by the ** third
brush'' system as explained for the type just
described. Drive is direct to the engine crank-
shaft through a silent chain.' No cut-out is used,
but when the motor-dynamo is connected; to the
battery by means of the starting switch, the
switch is allowed to remain closed 'and the in-
creasing speed of the unit when driven from
the engine causes the voltage as a dynamo to
rise to a point that recha^ggjg the battery. When
the car is operated at a^peed below about ten
miles an hour, the dynamo voltage falls below
that of a battery and the unit again becomes
a starting motor. A neutral position is pro-
vided on the starting switch for use when the
car is being driven at low speeds or when the
engine is idling. With the switch in this posi-
tion the motor-dynamo is disconnected and bat-
tery discharge is prevented!

Bosch Equipment. The dynamo is shown
in Fig. 272 and is used in connection with a
starting motor of the Rushmore type and having
the Rushmore form of drive to the flywheel.

The dynamo is a separate unit, shunt wound,
delivering 12 volts with a maximum output of

584 The Automobile Handbook

8 to 10 amperes at high car speeds with a par-
tially discharged battery.

A box mouuted on the dasb carries a volt-
aiimieter, voltage regulator, cut-out, lighting and
ignition switches and fuses. A small lever is
moved to cause the meter to show either volts
or amperes on the same meter.

Fig. 272
BOHch Dynamo
}{c}iiilalinn acts to maintain a steady voltage.
The iTguliitor consists of a small cylinder of
tai'lmii particles with one end of the shunt field
winding comicctcd to one end of the carbon pile
iind tile cori-i'sponding dynamo brush connected
to 1lif- other I'nd of the carbon. The shunt fii'ld
cucn^nt tliiis ])asses through the carbon. The
cni'lioii parlicU'S are held tightly compressed by
a ])lui]g(.'r titling inside the cylinder with a coil
si)riMg hoJiJing the plunger down. Under this
condilion the resistance of the carbon is very
low and allows practically the whole of the

shunt field current to pass without interruption.
An electromagnet forms part of the regulator
and is connected in shunt across the ^ dynamo
brushes so that its strength increases with the
rise in voltage. This electromagnet acts to pull
up on the plunger against the action of the
spring, and as the voltage rises the pressure on
the carbon is lessened in this way and the re-
sistance of the carbon pile increases rapidly as
the particles are loosened. This resistance in
the field lowers the voltage and output.

An electromagnetic cut-out is carried in the
dash unit housing with the voltage regulator.
These systems make use of the single wire,
ground return method of wiring. The start-
ing cable is, however, covered with a copper
sheath that assists in carrying the return cur-
rent to the battery.

Delco Equipment. A majority of Delco
applications have l)een of the motor-dynamo
type, this method being departed from for the
first time on some of the applications made on
1916 cars. The first Delco system to be used
consisted of a motor-dynamo that operated as
a starter at 24 volts and charged to six volts
for lighting and battery charging. The bat-
tery for this system consists of twelve cells
divided into four sections of three cells each.
By means of a two position multiple contact
knife switch carried in the battery box, these
sections were placed in series for starting and
in parallel for lighting and charging. The

complete- charging circuit diagram is Bfaown in
Pig. 273. ■■

The battery charge is controlled by a form
of wattmeter, called an ampere-hour meter.
Current flowing into the battery causes this
meter to revolve in one direction and current

Pig. 273
Charging Circuit of Deico 6-24. Volt

flowing out of the battery causes it to revolve
in the opposite direction. After a certain flow
has entered the battery, the meter has moved to
such a position that a resistance is inserted in
the shunt fleld winding of the dynamo and the
rate of charge is thereby reduced. Further

movement of the meter in the same direction
opens the shunt field current and further bat-
tery charge is prevented. "Withdrawal of cur-
rent causes the meter to reverse this movement
and the field circuit is first closed through the
resistance and the resistance is then cut out
entirely, allowing a resumption of full battery
charge.

Fig. 274 shows the complete circuit diagram
for this system. The magnetic latch is for the
purpose of allowing the driver to close the start-
ing switch and mesh the motor gears with the
flywheel when the clutch pedal is depressed. By
means of a small push button, usually on the
heel board, the latch magnet is energized and
the latch itself connects the starting gearing
with the clutch pedal. Depression of the
pedal then causes starting action as described.
The application of this system on a car, with
external wiring shown, is seen in Fig. 275.

A form of Delco motor-dynamo having two
separate commutators and two sets of brushes
is shown in Fig. 276. One of these commuta-
tors is for the dynamo generating action, while
the other is for starting.

When the unit is generating current for
charging the battery, for lights and ignition,
it is a simple shunt wound generator. It is
driven from the engine by an extension of the
pump shaft. The generator is driven at one
and one-half crankshaft speed, and in order
to compensate for the higher ratio when the

The Automobile Handbook 589

The Automobile Handbooh

Fig. 276
Deico Motor-Dynamo With Starter Switch Honoted
Above Flywheel Drive Gearing. A, Oil Hole.
B, Oil Hole. C, Grease Cup. D, Gear Shift
Yoke. B, Switch Operating Rod. F, Swlteb
Spring. G. Flywheel Gear. H, Motor Pinion
Gear. I. Clutch Shaft. J, Shift Yoke Rod. K.
Tripping Collar. L, ConUot Block Latch. H,
Contact Block.

The Automobile Handbook 591

592

The Automobile Handbook

unit is in starting relation to the engine, a sec-
ond one-way clutch is provided adjacent to the
forward housing. This clutch permits the arma-
ture to run ahead of the driving shaft during
the cranking operation.

Fig. 277 illustrates the Delco "Junior"
motor-dynamo and the starting switch is shown

Fig. 278
Delco Starting Switch

in Fig. 278. These units cannot well be shown
in their actual locations and are therefore shown
separate. Referring to Figs. 277 and 278, the
yoke H fits into the collar I which is pinned to
the rod D. The movement of the rod from the
starter pedal operates the gearing and the
starting switch.

The Automobile Handbook 593

When the starting pedal is pushed down it
pulls back the rod D and closes the contact E,
which completes the circuit between the battery
and dynamo armature. The closing of the cir-
cuit causes the armature to revolve slowly so
that the gear J will mesh with the motor pinion
as it slides along on its shaft. As the starting
pedal is pushed further down it continues to
pull the rod D, which opens the contact F,
breaking the circuit between the battery and
dynamo armature. This action of the rod at
the same time causes the motor brush switch to
drop onto the motor commutator, and the train
of gears to slide on its shaft until in mesh with
the motor pinion and the teeth on the flywheel.

The motor brush dropping on the commuta-
tor causes the circuit to be closed between the
storage battery and the motor armature, which
causes the motor to crank over the engine.

When the starting lever is released the motor
switch brush is raised from the motor commu-
tator and the train of gears is thrown out of
mesh, when the contacts F will automatically
close.

If the speed of the motor generator is above
'350 revolutions per minute, the cut-out relay,
Fig. 279, will close the circuit between the stor-
age battery and motor generator, thus permit-
ting the generator to charge the storage bat-
tery. If the speed of the motor generator is less
than 350 revolutions per minute, the cut-out
relay will remain open and all current for

594

The Automobile Handbook

ignition and lights, if they are in use, will come
from the storage battery.

Oil is conveyed to the ball bearings through
oil cup B and the small hole A in the front end
cover. This hole is made accessible by remov-
ing the upper front end cover. At the time 4
or 5 drops of light oil are put in the oil cup
B and the hole A, the grease cup C should be

CUT OUT
REL/\y

Fig. 279
Delco Reverse Current Cut-out

given 1 or 2 turns or replenished if empty.

The cut-out relay, Fig. 279, is located in the
rear end housing of the generator. This instru-
ment closes the circuit between the - generatoi

The Automobile Handbook 595

and the storage battery when the generator
voltage is high enough to charge the storage
battery. It also opens the circuit as the gener-
ator slows down and its voltage becomes less
than that of the storage battery, thus prevent-
ing the battery from discharging back through
the generator. The cut-out relay is an electro-
magnet with a compound winding. The voltage
coil or fine wire winding is connected directly
across the terminals of the generator. The cur-
rent coil, or coarse wire winding, is in series
with the circuit between the generator and the
storage battery, and the circuit is opened and
closed at the contacts A. When the engine is
started, the generator voltage builds up and
when it reaches about six volts a current pass-
ing through the voltage winding produces
enough magnetism to overcome the tension of
the spring B, attracting the magnet armature
C to core D, which closes the contacts A. Tliese
contacts close the circuit between the generator
and storage battery. The current flowing
through the coarse wire winding increases the
pull on the armature and gives a good contact
of low resistance at the contact points.

Delco systems used during 1915 consist of sin-
gle armature motor-dynamos, one application of
which is shown in Fig. 280. The armature car-
ries two commutators, one on each end or both
on the front end, the rear end commutator be-
ing for the starting motor action.

Two separate field coils are used ; a shunt for

the dynamo action and a series for the startiiig
motor action. These coils are both on the same
field magnet core and have separate terminal.^

The drive as g dynamo is from the rear ex-
tension of the pnmp shaft through a roller over-
running clutch which releases when the arma-
ture turns at high speed as a starting motor.

The starting motor drive is through a pinion
on the rear end of the armature shaft to a ring
gear on the flywheel. Two gears, fastened to-
gether, are free to rotate as a pair on an auxil-
iary shaft, the gears being slid along this shaft
by a yoke connected to the starting i>edal until
one is in mesh with the armature shaft pinion
and the other with the flywheel gear, complet-
ing the drive connection. A roller clutch is in-
corporated in the front one of the pair of slid-
ing gears, this clutch releasing while the arma-
ture is being driven as a dynamo.

Starting switch action is secured by normally
holding one of the motor commutator brushes
away from the commutator by means of a rod
connected to the starting lever or pedal. When
the lever or pedal is moved this rod is drawn
back so that the brush drops onto the commu-
tator under the action of its spring, completing
the circuit from the battery through the series
winding and armature. This rod is fastened to
the sliding gears so that they must be in mesh
before the brush can drop.

The dynamo brush that is grounded com-
pletes its connection to ground through a pi.:r

of contacts, one stationary and one movable,
Fig. 281. The movable contact is attached to
an arm on the movable starter brush in aucli a

/'GENERATOR
SWITCH,

Ftg. 281

Commutator End oC Delco Governor CoatroHed

Motor-Dynamo

way that the contacts open as the starter brush
di'ops onto the commutator. This prevents
dynamo action while the armature is acting to

start the engine.

No fuses are used, but there is a magnetic
circuit breaker, the electromagnet of which acts
to open the contacts from the battery and dy-

RECULATtNC

RESISTANCE
RESISTANCE

MANUAL V^ CLUTCH"

SPARK CONTROL

Fig. 282

namo to the lamp and ear wiring when 25 am-
peres flow. After the circuit breaker opens the
contacts continue to vibrate open and closed if

there is a flow amounting to five amperes. The
circuit breaker will not stay closed until the
ground or short circuit that is causing the leak
of current has been removed. The spring of
this current breaker should not be adjusted in
any way as it is a safety device.

Delco systems may have any one of three dif-
ferent systems for regulating the dynamo out-
put. One type consists of a differential or buck-
ing coil carried on the field magnets and con-
nected in series with the main line from the
dynamo brush to the dash switch unit.

Another method makes use of a coil of resist-
ance wire carried on a spool in the front end of
the dynamo case on the right hand side, Fig.
282. One end of the shunt field winding is
grounded through this resistance coil so that
the field current would have to pass through
the coil. Tliis high resistance would allow but
little flow and would weaken the field to such
a point that the output would be very low.
"When the dynamo is running at low speeds the
fi(^ld current, after passing to the lower end of
the r(^sistanee coil, goes to the ground through
an arm making contact with the coil. This arm
carries a contact which slides up and down on
the resistance coil, the arm being moved by a
cciilrirnpral governor attached to the ignition
dislril)nter shaft. As the dynamo speed in-
creases, the governor weights cause the movable
arm to raise so that its contact is farther from
the bottom of the resistance coil, and the field

The Automobile Handbook 601

Burrent must consequently flow through a great-
3r length of resistance wire before reaching the
sontact on the arm and passing to the ground.
Phis greater resistance in the shunt field circuit
Etllows less current to flow and by thus weak-
3ning the field cuts down the dynamo output
at high speeds.

The third system of regulation also causes
the shunt field current to pass to the ground
through a coil of resistance wire. This resist-
ance coil is wound on a spool and the spool is
3arried at one end of a rod, the other end of the
rod forming the plunger of a solenoid coil. The
strength of this solenoid increases with the volt-
ige, being connected in shunt with the brushes.
Increased strength of the solenoid pulls the
plunger farther into the coil. This solenoid coil
is in the upper end of a cylindrical housing,
md the resistance coil is carried below the sole-
aoid. The plunger and resistance are normally
m a low position but are raised by the solenoid
action. In the low position the resistance coil
3ips into a well partly full of mercury so that
the shunt field current does not have to pass
through all the resistance wire but passes into
:he mercury and to the ground from a contact
fastened to the mercury well. As the voltage
rises the solenoid becomes stronger, lifting the
plunger and pulling the resistance coil up out
)f the mercury well so that the shunt field cur-
rent must flow through a greater length of re-
dstance wire before reaching the ground. This

602 The Automobile Handbook

added resistance allows less current to flow
through the shunt field and consequently lowers
the field strength and the output of the dynamo.

Delco systems use either of two methods of
reverse current cut-out. One type comprises
a dash switch with five buttons. The three left-
hand buttons are for the lights, the two right-
hand being for the ignition. The button on the
extreme right is for the storage battery ignition,
the one next to it being for the dry cells. Each
of these buttons carries two contacts inside the
switch, one completing the ignition circuit and
the other completing the charging circuit.
When the engine is to be started either of the
ignition switches is pulled out. The current
then passes from the battery to contact (1) on
the switch, through the inner connection of
eitlier dry cell (Bat.) or storage battery (Mag.)
switch and out of terminal (6) to the shunt
dynamo winding and armature brushes. This
causes the dynamo parts to act as a motor of
very low power and the armature revolves
slowly so that the starting gears can be meshed.
As soon as the gears are meshed the motor
brush drops onto its commutator and completes
the starting circuit while breaking the dynamo
circuit as described before. The battery cur-
rent will then cease to flow through terminal
(6) but will flow through the circuit breaker,
whose points are held closed by a spring, and
througli the other connection on the switch but-
ton plunger, out through terminal (7) and to

The Automoiile Handbpok 603

604 The Automobile Handbook

the ignition coil. If the **Bat" button is pulled
out the dry cell current comes into terminal
(2) and out through (7) to the ignition coil.
When the engine has been started and the dy-
namo generates a voltage greater than the bat-
tery, current will flow from the dynamo through
the differential winding (if one is used) into
terminal (6), through the inner contacts of the
switch and out through (1) to the battery. If
the ignition switches are left closed with the
engine idle the battery will discharge through
the switch contacts and dynamo parts, these
switches acting as the cut-out with the dynamo
and engine idle.

The construction of Delco apparatus used
during 1916 differs from that already described
in one important particular. The outptit of
the dynamo when charging the battery is con-
trolled by the ** third brush'' principle.

One of the applications is shown in Pig. 283
and it will be noted that the armature and field
location, starting drive and ignition mechanism
is similar to the forms previously used. The
brush position is shown in Fig. 284. The action
is explained as follows : The full voltage is ob-
tained ])etween the large brushes and the volt-
age between the left hand large brush and the
small regulating brush is less than the full
pressure. This reduced voltage is applied to
the field coils. With the armature rotating, the
magnetic field is twisted out of its normal path
between the pole pieces, the degree of deflection

Tke Automobile Handbook

ling in direct ratio to the increase of speed.
bis deSection causes the magnetic flow to be-

Fig. 284
Brusb Mechanism ot Delco Motor-Dynamo

(me weaker at the points on the pole pieces
lat affect the flow into the "third brush" and
lis weakened field current compensates for
le higher output that would otherwise be
iused by increase of speed. Fig. 285 shows
te starting motor end of this same machine.

The Automobile Handbook

Auother application of the third brush dy-
iiamo does not make use of the raotor-dynainn

Fig. 286

Motor Brush Sivitcli Connections ol Delco Motor

DyDamo

coMiliinatiou, ))ut uses a separate seriea woum
iiKitoi- driving to the flywheel through a Beudb
screw.

The Automobile Handbook 607

Djneto and Entz Equipment. These in-
;aIlation8 make use of a combined motor-dy-
amo operating with twelve volts in some eases
ad with eighteen in others. A compound field
inding is used, series and shunt coils acting

Fig. 286
Five Terminal Dyneto-Entz Motor-Dynamo

■gether in starting and forming a reversed
riea controlled machine in generating. The
iversal of the direction of flow through the
ries field while generating causes this winding
1 oppose the shunt winding at high armature
teeds and the dynamo output is thereby limit-
l to a safe n

608 The Automobile Handbook

Dyneto and Entz outfits do not make use of
a cut-out of the usual form. The motor-dynama
is placed in circuit with the battery when the
starting switch is closed and this switch is left
closed as long as the machine operates. As
soon as the unit has started the ei^ue, the

Fig. 287
Four Terminal Dyneto Motor-Dynamo

engine causes the armature speed to increase
to a point at which the voltt^e is greater than
the ballery and charging then commences. If,
at any time, the armature speed falls below a
certain point the machine again resumes its ac-
tion as a starting motor.

The Automobile Handbook 609

The ignition is controlled by the same switch
that makes the battery and motor-dynamo cir-
cuit. With this switch in the **Off" position,
the ignition is inoperative and the battery is
disconnected from the motor-dynamo. With the
switch in the **0n" or ** Running'' position,
the ignition is on and the battery is connected
to the electric machine. A switch position mid-
way between the two mentioned is provided,
this position being called ** Neutral." With the
switch at ** Neutral,'' the ignition is operative
but the motor-dynamo circuit is open so that
the battery will not discharge, and the machine
will not act as. a starting motor at low engine
speeds.

The number of terminals differs on various
types ; one with five connections being shown in
Fig. !286 and another unit with four terminals
being illustrated in Fig, 287.

610

The Automobile Handbook

Gray ft Davis Equipment. The type of equip-
incut used from 1912 to 1914 is described below.

This system comprises two units: 1, tlie
starling motor; 2, the dynamo for chai^ag

battpry and lighting. The function of the dy-
namo is to furnish current for lamps and cur-
rent for the battery. The starting motor starts
thi' engine. Tbis motor is connected with the fly-
wlioel by gears, and when a starting pedal is

The Automobile Handbook 611

pressed the motor turns the flywheel and crank-
shaft and keeps turning until the engine * Spicks
up.'' The starting motor then automatically
ceases to operate.

The dynamo system includes the following:

1, a constant-speed dynamo, driven from the
engine or jackshaft by gear or a silent chain;

2, a governor, to take care of the varying speed
of the engine ; 3, an electric cut-out, to discon-
nect the dynamo from the battery when run-
ning below the charging speed ; 4, a battery to
operate the lights when the dynamo is not run-
ning at the necessary speed or when the en-
gine is stopped. This battery may also be used
for firing the engine.

1. The dynamo is of the compound-wound
type, designed to run at a constant speed of
1000 revolutions per minute. The system is so
wired that the series field is carrying current
only when the lights are burning. See Fig. 289.

2. The governor is of the simple, centrifugal
type, but operates a friction clutch of new de-
sign. In operation the clutch slips just enough
to hold the dynamo speed always at 1000
r. p. m., whether the engine speed corresponds
to a car speed of 13 or of 60 miles an hour.

3. The electric cut-out consists of an elec-
tro-magnet with a compound winding, the fine
wire part of which is connected across the dy-
namo terminals. Its function is, as stated, to
disconnect the dynamo from the battery when
the engine is running very slowly or is at rest.

612 The Automobile Handbook

The Automobile Handbook

613

n automatic switch of this nature were not
the circuit the battery would discharge
>ugh the dynamo when the dynamo was no
ler maintaining charging voltage,

A battery rated at 6 volta, 80-ampere

r capacity at a discharge rate of 8 amperes
irnished with this system sufficient to carry
full lamp load for ten hours or the side and
lamps for thirty hours. The arrangement

G14

The Automobile Handbook

of the switch connections is such that thf
(lynHino operates as a shunt-wound machine
\w\uW. charging the battery and as compound-
woiuid wlion supplying the lamps directly. Tliis
gives the battery a tapering charge.

Tlie wiring for tins system ia plainly shown
in tht; acrconipiiii.ving diagram. See Fig. 289.

The Automobile Handbook 615

The newer models of Gray & Davis equip-
ment make use of a separate dynamo or ignition-
dynamo with a combined output regulator and
cut-out carried in a housing on top of the unit.

The interior construction of the dynamo is
shown in Fig. 291, the particular model illus-
trated being. arranged for carrying an ignition
head at the drive end and providing a spiral
gear drive.

The cut-out and regulator are in the same
case and the one large electromagnet operates
both. This magnet carries two windings, shunt
and series. When the dynamo is idle the cut-
out contacts are open and the two regulator con-
tacts are closed, being held that way by their
respective springs. Fig. 292. Current enters
the shunt coil of the controller through the
grounded end and down through the terminal A
to the negative brush, thus receiving current
from between the brushes whenever the dynamo
runs. When the voltage rises to a point in this
coil so that the magnet overcomes the tension
of the cut-out spring the cut-out contacts close.
Current which has passed from the grounded
positive brush of the dynamo through the bat-
tery in charging, returns to the terminal B and
passes through the entire length of the series
coil on the magnet before going through the
cut-out contacts to the terminal A and negative
brush. Current which has passed through the
lamps returns to the terminal L and through
only a part of the series coil on the magnet

The Automobile Sandbook

Internal Connections of Gray A Darii Vlbrftting

Regulator System

The Automobile Handbook 617

before reaching the negative side. The more
lamps are turned on the more current they
take and the less current is left to pass through
the battery. It will therefore be seen that if
enough lamps were turned on to- leave nothing
going through the battery the part of the series
coil between L and B would carry no current
and the strength of the magnet would be weak-
ened. For the same reason it will be seen that
the more lamps turned on the weaker this coil
and magnet become. This is part of the regu-
lator action as will be explained.

The regulator action is as follows: Current
passes from the positive brush through the shunt
field and into the terminals F and Fl, then
through the regulator contacts which are closed
and back to the terminal A to the negative
brush. As the voltage passing through the
shunt magnet coil increases after the cut-out
has closed, its strength finally reaches a point
where the tension of the regulator contact spring
is overcome and the contacts are pulled open.
The current from terminals F and Fl must
now return to the negative brush through the
resistance wire coils seen between the two regu-
lator contacts, this resistance retarding the flow
and weakening the dynamo fields and conse-
quently lowering the output and voltage until
the weakened magnet allows the regulator con-
tacts to again close. This action causes these
contacts to vibrate and keep a steady output.
As explained above, the strength of the magnet

618 The Automobile Handbook

■

is decreased as more lamps are turned on, so
that the regulator contacts remain closed for a
longer time, and, as the resistance is not in the
field when they are closed, the output is allowed
to rise to care for the added lamp load.

The cut-out is of the simple electromagnetic
type. The action of the regulator allows the bat-
tery to receive a small charge even with all
lamps on.

Removable plates cover either side of the dy-
namo, allowing access to the inside without dis-
turbing any parts or wires.

A charge indicator is located on the dash or
cowl. The pointer turns upward if current is
passing to the battery and downward when cur-
rent passes out of the battery for any purpose.
If the pointer is straight across the battery is
neither charging or discharging. This indi-
cator should show charge at car speeds above
10 to 12 miles per hour.

The output of the dynamo may be tested by
turning on all lamps and disconnecting the wire
from terminal B. The lamps are then burning
directly from the dynamo and if they go out the
dynamo is at fault.

The regulator and cut-out may be tested by
connecting a wire from terminal A to terminal
B while tlie engine runs at a speed which would
correspond to a car speed greater than 10 miles
per hour. Tf the indicator then shows charge
when it failed to show this before the test the
cut-out or reorulator is at fault. Tf th6 indi-

The Automobile Handbook 619

cator remains straight across something is pre-
venting the dynamo from delivering its cur-
rent.

The lighting switch is of the rotary snap type
and carries all lamp and circuit wires on the
engine side. On the back of the switch are four
fuses in clips. Near the fuses are letters H, S,
R and B, indicating the fuses for head, side or
dimmer, rear and tail, ignition and horn cir-
cuits respectively.

North East Motor-Dyaamo

The starting motor drives into a flj-wheel ring
gear or crankshaft through sliding reduction
gearing and overrunning clutch. The starting
switch pull rod operates the sliding gear through

620 The Automobile Handbook

a coil spring so that switch contacts may close
whether gears are in position to mesh or not,
the first turning of the armature causing the
gears to snap into mesh under the action of the
compressed spring. One side of the starting
switch may be grounded or the lead from the
positive motor brush may be grounded. In
either case two wires lead to switch and start-
ing motor.

Nortii East Equipment. This starting and
lighting system makes use of a combined motor-
dynamo having two field windings, a shunt and
series. The series field is used for starting and
the two fields compound for generating. One
of these units is shown in Fig. 293.

The brushes and commutator may be exposed
by removing a cover from the .end opposite the
drive. The upper part of this cover, which en-
closes the brushes, is held in place by spring
clips, but the lower half is fastened with bolts
that are sealed at the factory. This lower half
encloses a combined cut-out and regulator. The
cut-out is of the electromagnetic type and serves
to connect the dynamo with the battery when
the generating voltage is sufficiently high to
make charging possible, also to disconnect the
])attery when the dynamo voltage falls below
that of the battery.

The regulator is of the vibrating reed type,
having two sets of contacts operated from one
electromagnet. The current output of the dy-
namo passes through the winding of the rega-

The Automobile Handbook 621

lator electromagnet and causes the contact to
open when the amperage has reached a certain
predetermined limit. With the contacts open,
the field current, which has previously passed
through the contacts, must flow through two
spools of resistance wire. The consequent re-
duction in field current prevents further rise in
output.

North East (equipment is of the two volt-
age type, the starting voltage being either 12,
16 or 24, while lighting and charging is ac-
complished at 6, 8 or 12 volts. Starting and
charging circuits are of the two wire type,
while lighting circuits may be either one wire
with ground return or two wire throughout.
A field fuse is carried in the brush and com-
mutator compartment of the motor-dynamo,
this fuse blowing out should the battery or
charging lines become disconnected while the
motor-dynamo is operating.

The -unit is driven from the engine and
drives to the engine through a silent chain,
with or without spur gear reduction.

Remj Equipment. Remy apparatus con-
sists of a variety of types, each one suited to
th^ particular requirements of the cars to
which it is applied. A complete internal cir-
cuit diagram of one of the separate unit sys-
tems with separately mounted regulator and
cut-out is shown in Fig. 295.

Remy equipment may be made up of all
separate units for lighting, starting and igni-

[>22 TliP Automobile Handbook

tioii, with or without Remy magneto or battery
ignition. The separate unit systems all maki'
use of a sliiint wound ilyiiaiiio of 6 volt mit-
put. The separate motors. Fig. 294, are of t'lnir
jKih', series wound type and operate on 6 volts.
A separal*^ dynamo may lie driven frimi a
filial't to the tiTiiing gear ease and have one nl"
the separate motors mounted ahove it, I'liriuiia:

Fig. 294
lieriiy Starting Motor With Bendix Drive

ilc> .li'ck'' iiistniment. The dynaam
two pole Kliunt wound and the motor
(■ .series wmind, both 6 volts. The
'ives down to the main shaft through
1)1' spur reduciion Rears, th« Inrpe gear
Lain di'Lve sliaJ't earrying an overrun-
Ii'Il wliieli rujis freo while the startiu)!

The Automobile Handbook

623

624 The AiUomohile Handbook

Another Remy system makes use of a motor
dynamo with only one armature. This machine
is of the four pole type, compound wound and
operates with 12 volts. No overrunning clutch
or device taking its place is used with the sin-
gle armature motor dynamos, these being di-
rect connected in all cases.

Reniy dynamos are also built with a mag-
neto type breaker mounted on one end of the
armature shaft with a magneto distributer car-
I'ied above it, thus forming a combined dyna-
mo-ignition outfit. The dynamos in this case
arc of the two pole shunt wound type operating
witli 6 volts. These machines are positively
driven at engine speed in four cylinder cars
one and one-half times engine speed in six cylin-
dc^r cars and twice engine speed in eights. A
sei)arnte 6 volt starting motor is used in cou-
ntM'tion.

The 12 volt motor-generators (as described)
ai'c nlso built with the ignition breaker and dis-
tributer added, forming a single unit having:
th(' functions of starting motor, dynamo and
ifrniter in one.

AViring for lighting, charging and starting
circuits may bo either two wire or one wire
witli grounded return. Switches, current in-
dicators, junction boxes and dimmer resistance
units varv with the make of car.

Regulation of the amperage is accomplished
in cither of two ways. One method is by the
third brush bcMug below one of the main brushes

The Automobile Handbook 625

on the left side facing the commutator. This
brash takes current to one end of the shunt
field winding, the amount of current flowing
through this brush becoming less and less as
the speed increases. The position of the brush
is not adjustable.

The other method of regulation consists of an
electromagnet carried in the same case with
the cut-out and operating to insert a coil of
resistance wire, also carried in this case, into
the shunt field circuit as the amperage rises.

The cut-out is of the electromagnetic type
with two windings, shunt and series. .The cir-
cuit should close in the neighborhood of ten
miles per hour, preferably at lower speeds. The
cut-out mechanism or combination . of cut-out
and regulator may be mounted on the dynamo
housing at the drive end over the armature
shaft or as a separate unit on the dash or other
convenient location.

The current output should be about 7 am-
peres at 8y2 to 12 miles per hour, rising to a
maximum of 10 to 14 amperes, depending on
the installation.

Starting motor drive may be through reduc-
tion gearing inside the housing as described
for the double deck instruments; or by chain
with overrunning clutch on separate motors
but without the clutch on motor-dynamos. Sep-
arate motors also use the Bendix type of in-
ertia pinion drive.

626 The Automobile Handbook

Starting switches are of two types, both mak-
ing the circuit complete without preliminary
contacts. One uses the conventional type of
tapered plunger, the other uses copper bands
sliding on two cylinders, the cylinders beings
made of insulating material and carrying con-
tact bands in such a position that the sliding
rings complete the circuit from one cylinder
to the other when fully depressed into position.
Either switch may act by push or pull rods or
foot buttons.

Fuses for each of the lighting lines are car-
ried in the lighting switch. A 20 or 25 ampere
fuse in circuit with the dynamo field is mounted
above the magnet in separate cut-outs or on the
base of combined regulators and cut-outs.

The Automobile Handbook 627

Rushmore Equipment. The Rushmore system
was originally manufactured by the Rushmore
Dynamo Works, but this company is now a part
of the Bosch Magneto Company, and the prod-
uct is known as ''Bosch-Rushmore" and
** Bosch/' The several unique features found
in this equipment are described on the follow-
ing pages :

The Rushmore Engine Starter. The Rush-
more electric starting motor, shown in Fig.
296, acts directly on the flywheel without in-
termediate gears, a pinion keyed fast on the
motor shaft meshing with a gear on the fly-
wheel rim. This pinion is normally out of en-
gagement. The closing of the starting switch
causes the pinion automatically to engage the
flywheel gear before the armature starts rotat-
ing. As soon as the engine picks up, the pinion
automatically slides out of mesh, and remains
out no matter how long the starting switch is
held closed. There is no mechanism except the
starting motor itself and the starting switch.

When the starter is not in use the armature
is held normally out of line endwise with the
pole pieces by means of a compression spring
contained in and acting against the hollow
armature shaft. Magnetic pull is employed to
engage the pinion. The foot button starting
switch has three contacts. At the first pres-
sure upon the button the armature is drawn
into the field with great force while rotating
slowly so that the pinion teeth will engage.
After the gears are fully engaged the thirr*

628 The AuiomobUe Handbook

contact applies the full force of the battery to
turn over the engine.

The motor is series wound and produces a
stronfi torque on startinfj. As soon as tlie en-

<:iiii' |>i<-l;s up. Ihc a ci- eh 'rated speed causes the
eoiinliT I'Ici'tni-iiKilivc t'circo in the motor to
ri'dui'c Ihr I'liiTrnt How ti» a value too small to
hol.l Du- aniititiiiT in line with the pole pieces
ayninst tlic end pressure of tlie spring. The

The Automobile Handbook

629

pinion thien slips out of mesh and remains out,
even with the circuit closed, because the cur-
rent required to run the motor free is too small
to overcome the spring. The armature will
not again move endwise into its working posi-
tion until it has stopped and the switch is
again closed. The turning force developed at
the flywheel rim is rated at over 400 lbs., suffi-

LAMPS

— O—

STOR&GE BATTERY

IRON

BALLAST

COIL

Fig. 297 — Diagram of Rushmore Lighting System.

eient to start the largest engine with ease. The
motor is wound for a 6-volt battery.

Rushmore Lighting System. Essential ele-
ments of this system are: 1, the dynamo;
2, storage battery, 6-volt, of 80 to 160 ampere
hours capacity, depending upon size of the
headlights; 3, switch and terminal block on

630 The Automobile Handbook

dashboard, which simultaneously switches the
headlights on or off and switches the ballast
coil in or out of circuit; 4, wiring and circuit
switches for small lamps.

Briefly the action of the dynamo is to reduce
the strength of the field magnet at high speeds
by means of counter excitation produced by a
few turns of magnet wire, called a ** bucking
coil,'^ on the field poles. The amount of cur-
rent passing through this bucking coil is deter-
mined automatically by the varying resistance
of a small coil of iron wire, called the ''ballast
eoil/' which is made in the form of a cartridere
fus(^ and carried in clips on the switchblock in
tlie main line l)etween the dynamo and the bat-
tery. See Fig. 297. The effect of controlling
the bucking coil by the current output is to pro-
duet^ an approximately constant current at the
hijrht'r s]>eeds.

Simms-Hufif Equipment. This apparatus
as jreiierally mounted consists of a combined
dy iic'i mo and motor with separate magneto ig-
nition. One wire system with a grounded re-
turn for all eireuits is used.

Tile motor dynamo is of the six pole type
and has a din*en»ntial compound winding. It
p'nenites 6 volts as a dynamo and operates with
12 volts as a motor. The drive for dynamo
])nr poses is by belt from the fan pulley and
enmkslinft. '\Vh(Mi operated as a motor the
rnirajremeiit is through a pinion which slides
on a counter shaft between the armature shaft

The Automobile Handbook 631

and flywheel ring gear and completes the me-
chanical connection.

The starting switch which makes the necessary
changes in connections for charging or start-
ing is located on the transmission case and the
operating parts also act to slide the gears into
mesh through the action of a stiff coil spring.
Should the gears not match exactly, the spring
compresses and allows the switch to close when
the first movement of the armature under the

Fig. 298

Simma-HufE Motor Dynamo

Starting eiirrent brings the gears into position

and the compressed spring forces them into full

engagement.

Regulation of output is maintained at a suf-
ficiently high value (15 amperes maximum) by
adjusting the tension of the driving belt. Ex-
eess-output is prevented by the differential ac-

632 The Automobile Handbook

tioii of the reversed series field winding and
by a separate regulator having an electromag-
net wiiich acts to insert resistance in tlie shunt
fii'lcl winding with rise of amperage. This
ckH'troniagnet regulator is carried in a housing
with the cut-out. The output is adjustable by
(•hanging tlie tension of the flat spring.

The cut-out is of the electromagnetic type
having two windings and the time of opening
and closing is adjustable by a small screw.

Two 6 volt, 35 ampere hour batteries are
carried in one box under the front seat, being
connected in series for starting and parallel
lor lighting and charging. A combined light-
ing and ignition switch is carried; inserting
the plug turns ignition on.

Headlight dimming resistance is carried on
the engine side of the switch and an ammeter
switch and an ammeter is mounted on the dash.

Splitdorf-Apelco Equipment. The eleetri-
cmI unit lor these equipments is shown in Fig.
2!Mi, ;nid its connections with the balance of
tile ii pp.! rat us is shown in the wiring diagram,
1^'ijr. ■{<>'>. The wiring shown applies to the
c'liiipiiieiit operating at 12 volts for starting
iiiid «l volts Um' charging and lighting.

These systrnis Use a combined motor dynamo
whii li iiijiy jdso enrry an ignition breaker and
(li>irihuioi' on n separate vertical head driven
tVojii one end of the motor dynamo unit. The
system is therefore of one or two unit type,
jio sej)arate starting motors being used. A

The Automobile Handbook

633

dynamo which does not act as a starting motor
is used on the Stanley steam car. All gas cars
use motor djiiamos.

The unit has four poles, three windings on the
£elds. One coil is ordinary shunt and acts as

Fig. 29 »
Splitdorf-Apelco Motor-Dynamo

a shunt in both generating and starting. The
output is controlled by a separate bucking
coil through which all current from the dynamo
passes, this opposing the shunt more and more
as the speed, voltage and amperage increase.
The third coil is a series winding for starting

634 The Automobile Jiandhook

motor action, though it also assists the shunt
while generating, making a compound dynamo
with bucking coil and a compound motor.

Two voltagi; cninljinations are used. One
charges tJie liattery and starts on 12 volts, us-
ing a six cell hattcrj- with all cells in aeries for

The Automobile Handbook 635

charging, starting and lighting. This is called
the straight twelve system.

The other system uses a six cell battery di-
vided in two sections of three cells each and is
charged with the two parts in parallel at 6
volts. This system uses all cells in series with
12 volts for starting while lighting is from the
parallel connections, thus giving 6 volt charging
and lighting and 12 volt starting, the proper
connections and changes being made in the
starting switch. This is the twelve-six volt
system.

Both types use separate electromagnetic cut-
outs mounted on the dash in all cases. The
cut-out carries two windings. The movable arm
carries a marker which shows the word OFF
on a dial whenever the contacts are open and
the word' ON whenever the contacts are closed.
ON simply indicates that the current is flow-
ing from the dynamo, but according to the
number of lamps turned on it may be going
to the battery or to the lamps or may be divid-
ing between them. The engine speed at which
the cut-out opens and closes may be changed by
a small screw passing through the cut-out
spring. This screw may be turned to either
lessen or increase the spring tension, thus low-
ering the cut-in speed or raising it accordingly.

The dynamo without starter action is a four
pole shunt wound machine operating at 6 volts.
Regulation is with a third brush which carries
all the current flowing to the shunt field.

636 The Automobile Handbook

U. S. L. Equipment. Two distinctly differon*
type's of eciuipment have been marketed by tli-
rnited States Light and Heating Company. Tli-
first type, which is described first, was used u]i
to and including part of the year 101 o. This
typ(* comprises a motor-dynamo mounted on th«*
engine crankshaft with the controlling eh*-
ments, cut out and regulator, carried in a hous-
ing on the driver's side of the dash board.

Tlie type referred to above is known as the
''external regulator" type, while the newrr
system is the "inherently regulated" type. This
jiewer system makes use of a cut out on the
<l«Msh, but secures regulation of current output
l)y alh)wi]ig the dynamo current, when exees-
si\'e, 1() react on part of the field, and by redue-
inir llie field magnetism in proportion to the
spee(l and output, a proper rate of dynamo
charge is maintained.

[■. S. L. Electric Motor Generator. In the
system emj)l()yed by the United States Light
cV: Heating Co., with which many automobiles
ai'e now e<juipp(»d, an electric motor generator
is an integral part of the gasoline motor ami
furnishes currc^nt for starting and lighting.
The syst(Mn includes, besides the motor gen-
eratoi-. an automatic current regulator, an oil
switch and a storage battery.

The motor gcMierator comprises a set of field
coils, armature and commutator and brush
rinu. Thes(^ ])arts replace the flywheel of the
gasoline motor, l)eing attached to the crank-

The Automobile Handbook

637

shaft in its stead. They are inclosed in an
aluminum case and dust ring.

When a starting button is pressed down, the
current from the storage battery starts the

irWMB|_ H^

motor generator. This revolves the crankshaft
of the gasoline motor. "With the switch of the
■gnition coil in either magneto or battery posi-
tion, the gasoline explosions commence. The
foot starting button is then released, when the

038 The Automobile Handbook

The Automobile Handbook 639

electric motor automatically changes into an
electric generator. As the speed of the gaso-
line motor increases, the generator gradually
begins charging the battery, restoring the cur-
rent discharged during the starting operation.

An automatic regulator, controlling the cur-
rent to the battery, is located in the center of
the dash. It has a charging indicator, the func-
tion of which is to show that the circuit is
closed at the proper time, or at a speed of 12 to
14 miles an hour, and that the circuit is open
when the car speed drops below about 10 miles
an hour or the motor stops altogether. The
regulator consists of a compound-wound mag-
net and a variable resistance with magnet bar
and contacts for controlling field current in
the generator.

The oil switch is included in this system to
change the electric motor into an electric gen-
erator upon the release of the starting button.

The type of U. S. L. equipment in most gen-
eral use at present does not use the externally
mounted combined cut-out and regulator but
secures regulation of the output as a dynamo
by means of a third brush system in which the
flow of current through one of the field cir-
cuits depends on the current flowing into one
of the brushes. The system is known as ** In-
herently Regulated.'' An electromagnetic cut-
out is mounted on the dash of the car and
serves the purpose of connecting the dynamo
and battery when the dynamo voltage is suffi-

640 The Automobile Handbook

cient for charging. The complete internal con-
nections for this type of application are sho\M3
in Fig. 303.

Above the cut-out are carried two fuses, cue
of six empere capacity and one of 30 ampere.
The six ampere fuse is in the field circuit and
will blow out should the battery lines become
disconnected with the dynamo operating. The
thirty ampere fuse is in the main charging cir-
cuit.

The touring switch used with U. S. L. equip-
in en t may be opened when the car is used on
l()]ig daylight runs, and by thus opening the
field and charging circuit of the motor-dynamo,
excessive battery charge is prevented. The
two lamp combinations in use with this type
aie shown in Fig. 303; one of these being a
tiiree wire system with 7 volt lamps, and the
other being the usual two wire system with
14 volt lain])s. Tn either case, starting is ae-
coniplislied with 24 volts and charging at 12
volts, the proper changes; in connections be-
in^ made in the starting switch.

The relative location of the parts of a V.
S. L. system having inherent regulation and 12
volt ])ressiire for all functions is shown in
Fiir. 304.

Wagner Equipment. Wagner apparatus
inny consist of a eomlnned motor-dynamo with
cut -out and starting switch mounted on the
unit, or of separate motors and dynamos with
a cut-out on the dynamo or mounted separately.

The AutomoiUe Handbook

ea.

^M8-,

Itod

Sid«

Tail

B3-I-I|l I I l|l B2-
Banery

Bl-i-

HI-

B2+

Battery

liwimh

Head

Side

Tail

Hm4

Side

DMh

14' Volt Lamp*

7-Voit Lamp*

NC_y

Staniat
Switck

Fig. 303

nternal Connections of U. S. L. 24-12 Volt In-
herently Regulated Motor-Dynamo System.

642 The Automobile Handbook

The motor-dynamo is a compound wound iiia-
eliine using the series fields for starting. The
output is controlled by taking the shunt lielJ
current through a 'Hhird brush" which is so
placed that excessive amperage is prevented at
liigh engine speeds.

On top of the unit is a housing in which is
an electromagnetic cut-out and also a rotary
drum starting and charging switch. This
switch makes such connections that starting is
accomplished with 12 volts pressure by ar-
ranging all battery cells in series, while charg-
ing and lighting are at 6 volts with the two
battery sections in parallel.

The motor-dynamo is driven from the engine
l)y means of a chain to the front end of the
crankshaft and is driven from the engine by
this same chain. The necessary gear reduction
I'oi- starting is secured through a planetary form
of ^^earing carried in a housing ahead of the
unit, this gearing being brought into play by
a l)rake band that is tightened by the same
<)[)erati()n with which the driver moves the
rot a i-y switcli to the starting position.

If the dynamo, motor and ignition are all
separate, tlu* dynamo is shunt wound. Four
hrushrs bear on the commutator, two receiving
the main charging current. The other two
biMishes are slightly nearer together. The sec-
ond pair of- ])rnslies carries the current to the
slnnit field and because of their location with
i-e Terence to each other act to decrease the cur-

The Automobile Handbook

rent flowing to the fleld at high speeds because
of the distortion of the path of the magnetism

Fig. 304
Arrangement of Parts In U. S. "L. Motor-Dynamo

System
between the field poles. This regulation action
prevents excessive charging rates at high speeds

644

The Automobile Handbook

ami oaiisf'R the output to be slightly decreased
at thcHu speeds. The action of this form of
reguhition is also to increase the output with
tint ineivase in hattery voltage so that the How
is greater to a battery when nearly charged
than when nearly empty.

mim

Fls. 305

Wafjner

Rtnrtinp;

Motor AVith Gear Reduction

ami

M, Brush

Holders

Tlir si a

'Hi

L' m

lor, FifT.

'iOr>. drives through

"I'll'' t-'i

II'

n'>]ii

'lion inid

chaiu to tlie front

li u\- 11,

Milks

lai'l. An

overrunning clutch

liinll

il<

IIm'

s]>roi-krt

on the crankshaft.

I.' St M 3-1

iijr

swil

li mak.-s

till' circuit complete

til. .Ill ;

].n.l

iiinary resistance, the clutch

MviiiinfT

t'h

I'UK

igement.

The Automohile Handbook 645

Westinghouse Equipment. Three distinct
types of Westinghouse apparatus are in use.
The first, and oldest, type makes use of a sep-
arate dynamo securing output regulation by
means of a bucking coil field as described in
the following pages, and having an electromag-
netic cut-out mounted on the dynamo. Another
type includes a separately mounted dynamo
having a vibrating reed voltage regulator and
an electromagnetic cut-out mounted on the
dash board or inside of the dynamo housing.
The third type consists of a combined motor*
dynamo having third brush regulation.

In generating current the machine acts as
a shunt wound dynamo, the reversed series
coil acting to regulate the amperage in a way
peculiar to these systems. One end of the re-
versed series coil is connected to one of the
dynamo brushes in such a way that current
flowing into the battery for charging passes
through this coil and by opposing the shunt
winding keeps the amperage down to a proper
point. The line which leads to the lamps from
both battery and dynamo is attached to a lead
from the differential winding in such a way
that current from the dynamo to the lamps
does not pass through the bucking coil. That
means that the amount of current which flows
through the bucking coil with the lamps off
is the entire amount from the dynamo going to
the battery, but as soon as the lamps are turned
on a part of this current passes to the lighting

646 The Automobile Handbook

lines and no longer goes through the bucking
coil. The reduced flow through the bucking
coil with lamps on allows the shunt field to
exert its effect without so much opposition and
the output accordingly rises to care for the
additional lamp load. Should enough lamps be
turned on to take the entire dynamo current,
none will be left to the bucking coil and the
dvnamo will act as a shunt machine without

opposition and give the fullest current flow
of which it is capable under these conditions.
Sliould still more lamps be turned on the ad-
ditional current will flow to the lamp lines
from the battery through the differential wind-

WESTINGHOUSE I WESTINGHOUSE I

Ope/) ' c/ased '

Fig. 306

AVostinghoiise Cut-out Used With Inherently Reg-
ulated Dynamos

inir. hut in an o])posite direction from which it
p;iss<'(l ill huckiiig the shunt action and will
i1h'I( fori' S(MV(' as an additional series winding
assist iiij^: the shunt and the machine is there-
fore (•oui])oun(l under these conditions and the
outpui is still furtlu^r increased.

All (lynanios of tliis type carry an electro-
iiia<zn('ti(' cut-out. Fig. 306, on the dynamo hous-
ing at the drive end just above the shaft, the

The Automobile Handbook 647

magnet carrying two windings bb is the usual
practice. This cut-out should close «t abdut
8 miles per hour and re-open at about 6 miles
per hour. It has no means of regulating the
time of opening and closing. The wiring for
this system is shown in Fig. 307.

•

The dynamo having voltage regulation is
of the shunt wound type and the regulator acts
to insert a resistance in the field when the
terminal voltage rises to the predetermined
limit. The operating parts of the combined cut-
out and regulator are shown with the cut-out
open in Fig. 308, and with the cut-out closed
in Fig. 309. The complete internal connections
of the voltage control dynamo with self con-
tained regulator and cut-out are shown in Fig.
310.

Whien the dynamo is being operated at a
speed below the predetermined ** cut-in speed",
the contacts of the cut-out armature are open,
the voltage of the dynamo being below that of
the battery. "When the speed reaches the **cut-
, in speed" these contacts are closed, connecting
the dynamo circuit to the battery circuit. The
** cut-in speed" varies from five to ten miles
per hour on high gear, depending upon the
gear ratio and wheel diameter of the particular
car.

The ''cut-in speed" can be observed by run-
ning the car, allowing it to increase in speed

The Automobile Handbook

slowly, and observing on the speedometer the
speed at which the car is running when the
cut-out contacts close, which is indicated by a
slight movement of the meter needle.

"'SfiJiai'&liiirC'Siii'" '

Fig. 307

Wiring of WesttnghouBe Ignition and Lighting

System, Inherently Regulated

Optn citita

Fig. 308 Figc. 309

Westinghouse Voltage Westinghouse Voltage

Controller, Cut-out Open Controller, Cut-out Closed

The regulator is so constructed that the cut-
out operates to disconnect the dynamo from the
battery circuit at a speed slightly below the
"cuWn speed". This enables the cut-out to

The Automobile Handbook

649

5ep the circuit closed, and not constantly open
' close it when the car is being run at speeds

Htgulaling Contceh

To B'atttry. B' ,

fK^

Voltage Regulating Screw

Cutout Armatuit^^^^^

ftegulat'mg Resistor.

l^/y/W'^/A

Xutout .
Contacts

Series Compensating Coil

Shunt Compen'
sating Coif-^

^ Coil

Regulator' Shunt Coil f"
generator Shunt Field

»A^-|

Commutator-

Brushes'

Fig. 310

ternal Connections of Westinghouse Self-Con-
tained Voltage Control Dynamo

)se to '* cut-in speed". This disconnecting
the dynamo from the battery circuit when

650 The Automobile Handbook

the dynamo voltage is below the battery volt-
age insures that the battery will not be dis-
charged through the generator.

The shunt fields of the dynamo are so de-
signed that a voltage in excess of the normal
voltage would be regularly generated when -the
dynamo is operated at high speed and no load.
This excess voltage is prevented and the volt-
age is held constant by the automatic voltage
regulator. When the dynamo is operating be-
low ''cut-in speed" the contacts of this regu-
lator are closed, and remain closed until the
armature is revolved at a speed which gener-
ates a voltage in excess of a predetermined
value. This voltage is fixed by the setting of
the voltage regulating screw which is adjusted
at the factory. When, due to the increased
speed of the dynamo, the voltage tends to ex-
ceed the value for which the regulator is set,
the regulating contacts open, opening the di-
rect shunt-field circuit and cutting in the regu-
lating resistance. This causes a momentary
drop in voltage so that the contacts close again.
This opening and closing of the contacts is
continuous, and so rapid as to be impercepti-
ble to the e}^.

Dynamos are also furnished with Ignition
parts carried on one end of the dynamo frame,
these parts consisting: of a magneto type
breaker whicli automatically advances the spark
by a pair of governor weights acting as the
break(»r cams and a distributor mounted above

The Automobile Handbook 651

the breaker. Otherwise the unit is the same as
the dynamos described.

The combined motor dynamos are four pole
compound wound machines operating with 12
volts, while the electromagnetic cut-out may or
may not be employed. When the cut-out is
used it is carried as a separate unit. These
maphines drive to the crankshaft direct through
chains or gears without the use of overrun-
ning clutches.

Almost all Westinghouse installations use the
single wire system with the positive side of
the circuit grounded in all cases. The ground
return for the starting motor is assisted by hav-
ing the cable enclosed in copper tubing which
is attached to the metal work of the car and
which is therefore free to carry the current to
the motor.

The lighting switch is usually of the push
button type. All circuits are fused, the cart-
ridge fuses being carried in fuse boxes which
provide for 3, 4 or 5 circuits in addition to the
line to the battery. The fuse for head and
tail lamps should be 15 ampere, for side and
tail 5 ampere, for tail alone 3 ampere and for
additional circuits such as the horn 15 ampere.
When 6 volt bulbs are used with short wiring
one of the fuses is replaced with a coil of re-
sistance wire so that the voltage to the lamps
with short connections may not be excessive.
With 7 volt bulbs this compensator coil is un-
necessary. Head lamps may be dimmed by

G52 The Automobile Handbook

throwing them in series or by arranging a re-
stance coil in one lead to the lamps. Junc-
tion boxes are used to centralize the connec-
tions and disconnector blocks are used for al-
lowing body removal. Either an ammeter or
voltmeter may be used, the ammeter being con-
iK'cted on one of the battery lines to the lamps
and dynamo in the usual way while the volt-
meter is directly connected to the two sides of
the battery, indicating the voltage at all times.
The current drawn by the voltmeter is so small
tliat it can be neglected in every way.

Separate starting motors are of the four pole
type, scries wound with the field coils carried
on two of tlie four poles, and operate with 6
volt«.

Stai'ting motors may drive the engine in any
of five different ways. One system drives from
a ])iiiion on tlie armature shaft to a larger spur
gear on a counter shaft, this larger gear hav-
iiijr an ov(^rrunning clutch built into it.
]\r()nnl(Ml on the coimter shaft is a small pin-
ion whkli is free to slide on the counter shaft
until it meshes with teeth on the flywheel rim.
Tliis slidiiit^ ])inion is moved by a yoke and rods
fi'om tli(' foot pedal, these operating rods also
()]>(M'a1iiig th(* switch. The first movement of
tli<' ]KM]al closes the circuit through preliminary
contacts and resistance ribbon, causing the
stai'tin<2: motor to whirl with little power.
Further movement of the pedal breaks this
electrical connection but leaves the motor spin-

The Automobile Handbook

653

ning while the movement pulle the gears in
mesh. After the gears are meshed the switch
has traveled to a position in which full eon-
taet is made and the motor turns the engine.
Releasing the pedal opens the switch and the
gears are thrown out of mesh by a coil spring
in the gear housing.

Ittternal Connections of WestlnghouBe Masnetic
Pioion Shift Starting Motor Drive

Another system uses the same arrangement
of gearing between armature shaft and fly-
wheel teeth but the gear meshing and closing
of the switch is accomplished by solenoid ac-
tion in place of by foot power. Three switches
are used, Fig. 311, one being a push button on
the dash marked "start," another being a
small cylindrical housing through which the
large starting cable runs and to. which the wire
from the dash button also leads and the third
being the starting switch which is connected to
the shifting pinion as previously described.

654 The Automobile Handbook

Pressing the dash button allows current to
flow from the battery to the small cylinder-
shaped switch and through the windings of a
magnet on this switch. This magnet pulls the
contacts closed which allow the battery current
to pass through and to the large starting switch.
The large switch contains a powerful solenoid
coil through which the current then flows and
out through a small auxiliary wire to the
ground. The solenoid immediately pulls on
a plunger which is attached to the sliding gear
and starting switch contacts and the action of
closing the contacts and sliding the pinion into
mesh is done by the pull of the solenoid in the
same way as previously described for the foot
])iitt()ii action. As soon as the engine starts
it runs the dynamo and the voltage of the
dynamo rises to a point equal to the battery
v()llag(\ This balance of pressure prevents any
more current from flowing through the switch
()])erated from the dash button and the main
starting eal)le contacts open whether the dash
button is released or not. This -kills the sole-
noid action and all parts return to normal
positions.

The starting motor may also drive to the
crankshaft through gearing or chains with
ovcriMinning clntch in which case the starting
switch mak(\s full contact in the first position.

Some installations drive to the fly-wheel by
means of a Bendix type of application.

The Automobile Handbook

655

Steering Qear— Principles of. In . steering
gears the generally accepted principle is that
known as the Ackermann-Jeantaud, which was
invented in 1878 and is a modification of the

Pig. 312
Designing Steering Knuckle Arms
original Ackermann principle. In the Acker-
mann-Jeantaud system the steering knuckle
arms OL and O^L, when produced, meet in the
plane of the rear axle or in this plane produced
as shown by illustration, Fig. 313. The reader
will appreciate that when the tie-rod L L is in

65r.

The Automobile Handbook

roar of the front axle, the steering knuckle
arms, OL and O'L converge, as illustrated, but
Khould the tie-rod be in front of the axle, these
arms diverge. Strictly speaking, the points A
and AI, which are supposed to be in the aile

t-T

/ /

r;;P

4^.

-^•^

'-■ ■-,

>'i^

\ I

" s

\, ' *

K \

I \ \

'-•- \

/ ^ *

r -

'■^ »

\ *■

\
\

"■. \~

pliini', are not sn. and the axle line A, AI, is »
Inrifii'nt to tlio curve in which the points of con-
viTtrciicc will full in a complete sweep of the
stfcring wlieels from axle to axle.

The Automobile Bandhook

657

It will be realized from the foregoing ex-
planation that the dimensions and proportions
of the steering axle parts depend on the wheel-
base of the ear, inasmuch as with a longer
wheel base the distance that the lines would be
produced would be greater with the increase.

658 The Automobile Handbook

Several makers have, however, discontinued
the design of steering knuckles on this princi-
ple, preferring to design them as illustrated in
Fig. 312, in which the produced axis of the
front wheels, A and B, intersect the axis of the
rear wheel at a given point 0. With this con-
dition fulfilled, the vehicle will travel around 0
as an imaginary center. Enthusiasts of this
method of construction agree that the Acker-
mann-Jeantaud principle is sufficiently accu-
rate for angles of not more than 30 degrees, but
for angles varying from 30 to 45 they claim less
wear on their tires by the latter construction.
The exact arm for the angles in a steering gear
of this nature will depend largely on the wheel-
base of the car as well as the difference between
the steering pivots A and B.

Steering Gear — Types of. Fig. 314 shows a
sectional view of the nut and segment type of
steering gear, in which there is a worm D on the
steering column that engages with the nut E.
On the front or gear face of the nut is a rack F
which meshes with the sector G, so that as the
steerino" wlieol is turned right or left the nut is
raised or lowered and the requisite movement
im])ai'ted to the radius rod H. In certain screw
and nut steering gears the sector is not required,
the constrnetion ])eirig a screw on the steering
cohniui on wliieh works the internally threaded
nut, and on (Mther side of this nut are trunnions
with links which connect with the axis carrying
the radius arm.

The. Automobile Handbook

659

Steering Gear — ^Lost Motion in. If the gear
of the worm and sector type it may be that
lese two elements are not held ia the proper
ilation to each other. Fig. 315 shows a dia-
."•am of this type of gear, and illustrates plainly
le point where lost motion wi|l be of the great-
it detriment. When the wheel is turned, if
lere is the slightest end play, the wheel shaft

Lost
ToWop

Fig. 315

ill respond, but the geared sector will not,
ntil all the end play is taken up, and as
rains come on from the road wheels, the sec-
)r will rotate to and fro, causing the shaft of
le steering wheel to reciprocate and thus al-
'W the road wheels to wobble. To overcome
ns it is necessary to replace the thrust washer,
tnere be one, and if necessary, introduce a

(510 The Automohile Handbook

washer, made of phosphor bronze, of suitabk
thickness to take up all the end play of the
steer iiiii: wheel shaft.

Some lost motion will follow if the worm is |
not set on the pitch line, in its proper relation
to the sector; this 'will be true if the bushings '
arc worn, and when a new thrust washer is
made and fitted into place, if the lost motion is
still j^reater than is desired, the only thinp re-
maining^ is to replace the bearing brasses. When
the jrear is dissembled it will be possible to di-
me* nsion the same, and determine by measure-
ment if there is any great amount of journal
wear, tlius rendering the task less troublesome.
since the brasses may be replaced without wait-
in*;' to determine the remaining lost motion
llirou^li actual trial.

As a rule, it will be found that the lost motiop
is due to end play, just as the illustration shows.
cUkI not to worn-out journal brasses on whieh
th«' wear is far less than it is in thrust. If the
<:(';) r is irreversible, or nearly so, as it is in many
niiloiiiobiles, a little lost motion is to be ex-
pected owinj^' to the smallness of the angle of
the worm, which can only be irreversible if the
anirl'' is sucli that a little lost motion will be
present and unavoidable.

Caki: of Stkkkixc; (iEar. The steering gear
is a very important part of the car, and, as thn
snt'ety of th(» oc<'upants may be endangered by
any hindin^, the autoist should give it even
inor<* "ar<'t'ul attention than the other parts.

TJie Aulomobilr Handbook

The gear should be taken down, given a thor-J
ongh cleanint; and examined for possible j

662 The Automobile Handbook

In case the steering action is stiflf and tiie T/fie^l
turns hard, the ball joint may be out of adjust-
ment due to wear; the steering link may be
bent, or the cause may be insuflBcient lubrica-
tion. If there is any considerable amount of
backlash, the cause may be looked for in the
joints of the levers, in the swivel pin, or iu
loose bearings.

Tires, Care and Repair. Aside, from gaso-
line the greatest expense in the upkeep of a
motor car is the tires, and much of the present
excessive tire wear may be reduced with reason-
able precaution and care. There are ten com-
mon tire diseases, as follows : wheel out of align-
ment, linder-inflation, use of anti-skid chains,
skidding, running wheels in car tracks, neglect
of casing repairs, tread cuts, running in ruts,
stone bruises, use of inside protectors on new
tires.

When a tire is on a wheel which is out of
alignment the result is that the tire is scraped
across the surface of the road and the resulting
friction causes the tire tread to wear rapidly.
The action of the tire on the road is crosswise
at the same time that the tire revolves with the
wheel. Thus the tire receives its usual wear
pins the wear due to the scraping. The tread
of a tire which has been run on a wheel out of
aliprnniPiit presents a rough appearance, that
whicli would bo given it were the tire held
against an emery wheel for a while. Sometimes
tho fabric shows in places, and this is especially

The Automobile Handbook 663

true of wheels which are wobbly. It is advis-
able to line up the wheels of a motor ear about
every three months, and if one is found which
does not run true, the condition should be cor-
rected immediately.

Perhaps as much harm is done by running a
tire under-inflated as by anything else. Under-
inflation, as the name implies, means that the
tire is running with insuflBcient air pressure.
Such a tire appears usually with a series of hilly
blisters running around the tread. The blisters
are caused by the separation of the fabric from
the tread due to the excessive heat generated in
an under-inflated tire. With insufficient air the
flexing of the walls of the tire causes heat to
be generated and this heat acts on the cement
between the tread and fabric and in a short time
the two separate, causing a blister to appear.
Even in the summer a tire should not be run
under-inflated. The common version is, that if
the ordinary pressure is 80 pounds, a reduction
of possibly ten pounds is made for summer
weather. The belief is that the heat of the at-
mosphere will soon raise the temperature of the
air in the tire and thus cause the pressure to in-
crease to the proper point. This practice is not
advisable, as there is undue wear on the tire
while the pressure is being increased by the rise
in temperature, and also because the pressure
will drop as soon as the tire cools. The cure
for under-inflation need hardly be stated. Keep
the tires inflated to the pressure specified by

664 The Automobile Handbook

■

the maker, which is usually 20 pounds per inch
of cross-section. Thus, a 4-inch tire should carry
80 pounds pressure. It matters not if the press-
ure is a little more, but it does if the pressure
is less than that for which the tire is designed.
A tire guage, such as is sold for one dollar,
should be one of the important instruments in
the motorist *s tool kit.

When anti-skid chains are applied to the tire
too loosely or too tightly, the result sometimes
is a cut tread. These chains should be placed
on the tire so that they fit snugly and then no
material tire wear will result.

Running a wheel in car tracks may soon cause
the sides of the tire to become chafed, and in
some instances the wear is so much that the
tread loosens at the sides and begins flopping
around. The same appearance may result if
the car is driven very close to the curb and the
side of the tire made to scrape the stone.

Little cuts in the casing often result in the
casing being unfit for use in a short time. When
a small cut appears and the tire is operated,
dirt and water get underneath the tread. This
dirt works its way around the tire under the
tread with the result that the tire is soon loose.
Water, as everyone knows, is detrimental to rub-
ber, and more so to the fabric. Fabric begins
to rot in the presence of water. The small cuts
may be plugged with mastic.

Often a cut appears in the tread and an in-
spection finds that the fabric is injured also.

The Automobile Handbook 665

In such an instance the blowout patch is the
first resort. The patch, if wrongly applied,
sometimes becomes wedged in the fabric. cut and
in this way hastens a blowout. The best way
to treat a tire with a reasonably large tread cut
is to have, the cut vulcanized immediately. In
fact, even small cuts should be vulcanized at the
first opportunity. The owner may say that the
cost of having the tire vulcanized every time it
is cut is expensive. It may seem expensive at
first, but the saving in tire wear and repair later
overbalances the comparatively small cost of
vulcanization.

In the fall especially country roads present a
mass of hardened ruts which play havoc with
tires. These hard indentations house the tire
for a while and then the driver will go over the
rut. The driving in and out of these ruts ere*
ates a condition which puts a tire in the rut-
worn class. The sides of the tread begin to show
rapid wear and sometimes the wear is great
enough to cause a weak spot in the tread, with
the result that the tire blows out.

Stone bruises cause a great percentage of tire
failure. "When a tire runs over a stone, one as
big a man's fist, there is a possibility of the
fabric becoming broken. A broken fabric soon
causes a blowout, so it remains for the driver
to prevent as far possible running over such
stones. Small stones sometimes present sharp
edges which cut the tread and thus make an
entrance for dirt and water. Stone bruises are

666 The Automobile Handbook

hardly visible from the outside, as the condition
is one of a fabric break, as mentioned above.
The result of a stone bruise may be seen by ex-
amining the inside of the casing, which will
show clearly that the fabric is injured.

Some makers state that the use of .inside pro-
tectors on new tires is not advisable, as these
appliances create an undue amount pf heat in
the tire and thus hasten wear. For old tires the
inside protector is perhaps the best accessory
marketed for lengthening tire life. Some own-
ers have obtained as much mileage with old tires
and inside protectors as they have from new
tires operated without protectors.

Tire Vulcanizing. Absolute cleanliness is
necessary in all vulcanizing work. No matter
how good a vulcanizer you have or what kind
of repair stock you use, the smallest amount of
oil, grease or dirt will greatly impair the work.
Therefore clean every repair thoroughly with a
cloth or brush dipped in clean gasoline and
roughen the point of repair with a rasp or
coarse sandpaper while still wet.

Tires must be dry before beginning work on
them, otherwise a porous patch will result. If
you think, for any reason, that the canvas in
the casing is even slightly damp, clamp the
vulcanizer looselv over the tire for ten or fifteen
minutes before applying the first coat of cement.
Interpose a piece of waste or something of the
sort between vulcanizer and tire to permit the
escape of moisture.

The Automobile Handbook 667

It takes from fifteen to twenty minutes to
vulcanize a layer of Para one-sixteenth of an
inch thick if the thermometer is kept at 265
degrees, and five additional minutes for each
additional sixteenth of an inch. Vulcanization
will occur equally well at all temperatures be-
tween 250 degrees and 275 degrees. The lower
temperatures require more, and the higher tem-
peratures less time than stated above.

Inner tube punctures. Clean the tube thor-
oughly with gasoline and coarse sandpaper, for
at least an inch all around the hole (be careful
not to get gasoline inside the tube) ; then wipe
with a cloth moistened with gasoline. When
the gasoline has evaporated cement the edges of
the hole and apply a thin layer of cement to
the tube for three-quarters of an inch on each
side of the hole. Let the cement dry until
the gasoline has all evaporated and the cement
is solid enough to resist the touch. ''Tacky"
is the usual word. Apply a second coat and let
dry as before.

If a small hole, fill even with the surface of
tube with layers of Para rubber cut the size of
the hole, taking care that the Para sticks all
around the edges. If a simple puncture, place
a narrow strip of Para rubber over the end of
a match and insert it into the hole. Cut off
what protrudes outside the tube. Cut a patch
of Para one-eighth larger than the hole or punc-
ture and apply over same. Then cut another
patch one-half inch larger than the hole and

668 The Automobile Handbook

apply over the first. Cover and apply vulcan-
izer.

Repairs of this sort are to be vulcanized for
fifteen or twenty minutes at 265 degrees.

Inner tube cuts and tears. Clean as directed
both inside and outside of tube; coat edges of
cut and inside and outside of tube with cement
and ,let dry. The cement should extend three-
fourths of an inch back from the cut.

Cut a strip of Para rubber ac wide as tube
is thick and stick on edge of cut; cut a strip
one-half inch wide of Para rubber cured on one
side, place it inside of tube under tear with
cured side down, bring edges of tear together
and stick them down to this strip. If you do
not have any of the Para cured on one side
regular Para may be used after cementing a
piece of paper to inside of tube opposite the cut
to prevent patch from sticking to opposite side.

Apply another strip of Para rubber one-half
inch wide on the outside of the repair. Vul-
canize for twenty-five minutes.

The first step in making a casing repair is,
just as in the case of all tire work, to thoroughly
clean the point of repair. Apply from one to
three layers of cement, allowing each to dry.
If the canvas is exposed, as in a scalp cut, put
on enough cement to fill the pores of the canvas
and loave a smooth surface when dry. Fill the
hole not quite level with surface with Para rub-
ber. The best results are obtained when casing
repairs are slightly concave. If filled too full,

The Automobile Handbook 669

the rubber will expand and flow over onto the
unprepared surface in a thin film that will soon
peel up and cause trouble. Moreover, a pro-
truding patch will receive more than its share
of hammering and will undoubtedly split open.

Tonneau. The name or term used in connec-
tion with the rear seats of a motor car. • Liter-
ally the word means a round tank or water
barrel.

Torsion Rod. When the manner in which
the power is transmitted from the change-speed
gear to the rear axle on the shaft-driven car is
considered, it will be apparent that the turning
of the shaft imposes a twisting strain on the
whole rear end of the car, and that if it were not
for the frame, and the weight of the car on the
ground, there would be a tendency to revolve
the rear of the chassis around the shaft, rather
than to turn the wheels. But it would be bad
practice to permit this strain to fall on the frame
and hence the office of the torsion rod, which is
designed to prevent its reaching that member.
On cars that are not provided with independent
torsion rods, it will be found that the housing
of the propeller shaft has been made corre-
spondingly stronger, and that its support has
been designed to enable it to act in this double
capacity. This represents a simplification of
design that will be found on quite a number of
cars, as it eliminates a part exposed to mud and
dirt.

Traction of Driving Wheels. A horse which

670 The Automobile Handbook

exerts a pull of about 375 pounds continuously
for an hour and goes a distance of one mile in
an hour is working at the rate of one horse-
power. If for any reason the horse is unable to
exert as much as 375 pounds pull when going
at the rate of one mile per hour, he is thereby
prevented from working at the rate of one
horsepower.

The same rule applies to a motor car. When
the road is not slippery there may occur a con-
dition which does not appear with horse trac-
tion ; that the tires fail to adhere to the ground
owing to insufficient weight on, the driving
wheels. In such a case it is impossible for the
motor-car to exert a push of 375 pounds with-
out skidding the wheels, and thus it would be
impossible for it to work at the rate of one
horsepower. With underpowered motor-cars
this difficulty does not occur, but to develop 10
horsepower at the rims of the driving wheels
while covering the ground at the rate of one
mile per hour, the car must exert a push on the
road of 3,750 pounds. This is, on touring cars
of ordinary weight, impossible, because the
weight on the driving wheels is invariably less
than 3,750 pounds, while the adhesion with the
road is only a fraction of the weight on the rear
wheels. As the specnl rises, however, the push
necessary for 1h(^ development of 10 horsepower
goes down until at 10 miles per hour a push of
375 pounds inc^ans 10 horsepower.

Thus a 40 horsepower car, if it could start

The Automobile Handbook 671

work with the activity of forty horses, would,
Avhile it was moving at one mile per hour, exert
no less a push than 40 x 375, which is equal to
15,700 pounds. This tremendous push is ren-
dered impossible by the fact that the wheels of
a c^ weighing 2,000 pounds only grip the
ground enough to exert about 750 pounds push.
Beyond this point they will skid.

This shows that a high-powered car, when the
car is moving slowly, cannot develop its full
power unless the road wheels are capable of ad-
hering to the ground sufficiently to transmit
this power. As a rule only about 0.6 of the
weight of the car is on the driving wheels, and
of that only 0.625 is available for the adhesion
(owing to the coefficient of friction between
rubber and road being 0.625). So a 10 horse-
power car weighing 2,000 pounds cannot exert
its full power when the car is starting, nor until
it is traveling at 5 miles per hour.

It would be wrong to contend that on all
cars having the weight distributed as at pres-
ent, a 60 horsepower motor is useless, but it is
needless to say that the output of such a motor
is not availabe at starting or at any speed
under 30 miles per hour, although the whole
power is more needed then than at any other
time. The remedy which suggests itself is by
using all the adhesion of the car, that is, to
drive with all four wheels.

Transmission of Power — Efficiency of. The
efficiency of various forms of drives between

t)72 The Automobile Handbook

the motor and the driving wheels of a motor
car may be estimated as follows :

Single-chain, with direct drive on the high
speed, between the motor and rear axle — 85 per
cent.

Two-chain drive, from motor to speed-change
gear, from speed-change gear to rear axle — 75
per cent.

Quarter-turn or right-angle drive, with dou-
ble-chain drive to free rear wheels — 70 per
cent.

Longitudinal shaft drive, with universal
joints and bevel gear in differential case — 65
per cent.

Transmission Shaft. The square transmis-
sion-shaft used on several highest-powered cars
is a nickel stoel forging with .25 to .30 per cent
of carbon. The treatment is about as follows:
First heated in lead bath, then transferred to
the cyanide, where it remains 20 minutes, then
dipped in cottonseed oil. The shaft then goes
to the furnace and is heated to 1,400 degrees
Falirenlic^it. When removed from the furnace,
only the part of the shaft upon which the slid-
ing gears operate is dipped in oil. This class
of steel before treatment averages 86,000 tensile
strength, after trc^atment 125,000 to 130,000.

Transmission. See Change Speed Gearing.

Trouble Location. See Knocking, Pounding,
Preignition, etc,

Twelve-Cylinder Engine. See Engine, Eight
and Twelve Cylinder,

The Automobile Handbook 673

Unit of Heat. The heat unit or British ther-
mal unit (B. T. U.) is the quantity of heat re-
quired to raise the temperature of one pound
of water one degree, or from 39^ to 40° F., and
the amount of mechanical work required to pro-
duce a unit of heat is 778 foot pounds. There-
fore the mechanical equivalent of heat is the
energy required to raise 778 pounds one foot
high, or 77.8 pounds 10 feet high, or 1 pound
778 feet high. Or again, suppose a one-pound
weight falls through a space of 778 feet or a
weight of 778 pounds falls one foot, enough
mechanical energy would thus be developed to
raise a pound of water one degree in tempera-
ture, provided all the energy so developed
could be utilized in churning or stirring the -wa-
ter.

Vacuum Fuel Feed. See Fuel Feed, Vacuum.

674 The Automobile Handbook

Valves.

Sleeve Val\'es. During the last few years
there has been placed on the market a type of
engine that does not have poppett valves, but
which has a type of valve known as a "Sleeve
Yalve." See Engine, Sliding Sleeve Type.

Sleeve valves are made by placing two sliding

Fig. 317
Sliding Sleeve Valves

sleeves belwci'ji the piston and the cylinder
«-alls, Fig. ;{17. These sleeves are shaped like
a seetidii of tubing and are about an eighth of
an inch thick. There are holes or Blots cut
Ihcoiigli tlifi sWves near the top, that is, in the
pari of the sleeve nearest the cylinder head.

The Automobile Handbook 675

The holes, or ** ports*' as they are called, are
placed so that when the sleeves are placed in a
certain position the holes are opposite each»
other. When they are opposite each other they
will let the mixture through into the cylinder or
let the burned gas out into the exhaust pipe,
depending on which thing it is necessary to do.

The lower ends of the sleeves connect with
small connecting rods which are worked up and
down by eccentrics on the shaft that takes the
place of the cam shaft. These small connecting
rods move the two sleeves up and down so that
when the piston is ready to start down on
the inlet stroke two of the openings come oppo-
site each other, one opening in each sleeve.
These two openings are brought opposite the
opening that goes to the carburetor at the same
time they are opposite each other so that the
fresh mixture can be drawn into the cylinder.

After the piston passes bottom center the
sleeves are moved so that the openings are not
opposite each other or the opening to the car-
buretor and the fresh gas is shut off.

When the piston is most of the way down on
the power stroke two ports on the other side of
the sleeves, one opening in each sleeve, are^
brought opposite each other, and at the same
time opposite a hole that opens into the exhaust
pipe so that the burned gas can get out of the
cylinder. After the piston finishes the down
stroke, goes up on the exhaust stroke, and is just
past top center, the two openings are moved so

676

The Automobile Handbook

that they close the hole into the exhaust pipe
and then the inlet openings come opposite each
other again.

These sleeves are adjusted to open and close
at just the right time by adjusting the length
of the small connecting rods.

The opening and closing of the ports should
come simultaneously with the opening and clos-
ing of the inlet and exhaust valves in a poppett
valve engine.

R(JT.\RY Valves. Other engines are made
without either poppet or sleeve valves but with
a type of valve called a "Rotary Valve."

The Automobile Handbook 677

Rotary valves, Pigs. 318 and 319, are made
by having a long round shaft run along the
side of the cylinders near the cylinder heads.
Holes are bored through this shaft so that the
, holes come opposite openings into the cylinder
or combustion space and at the same time open

Fig. 319
Engine With Separate Rotary Valves

into the pipe leading to the carburetor or to the
exhaust pipe, according to the position the pis-
ton is in and the stroke it is making.

This long shaft or valve is set in a position to
open the inlet holes at the same time as the
inlet valves should open in a poppet valve

678 The Automobile Handbook

motor, to close the inlet holes at the time the
inlet valves should close, and to open and close
the exhaust holes at the same time as the ex-
haust valves should open and close in a poppett
valve engine.

The rotary valve is driven from the crank
shaft by gears or chains so that it turns half as
fast as the crank shaft, just the same as the cam
shaft would turn.

Disc Valves. There are still other engines
made with a type of valve known as a ''Rotary
Disc Valve." These valves are in the shape of
a piece of round iron as large around as the
top of the piston and about a quarter inch thick.
They are placed on the top of the cylinder and
fastened to gears so that they rotate or turn
around.

Holes are cut through the disc so that they
come opposite holes cut through the cylinder
head. Some of these holes connect with the
pipe that goes to the carburetor and others con-
nect with the exhaust pipe.

The discs are made to turn so that the inlet
holes and exhaust holes are opened and closed
at the same times as the inlet and exhaust
valves are opened and closed on a poppett valve
motor.

Pitted Valves. A valve in a pitted con-
dition eausos l)ad compression, and the exhaust-
valve should be ground occasionally. After
grinding the exhaust-valve be sure that there
is ample clearance between the valve and the

The Automobile Handbook 679

lifter. It should have not less than one hun-
dredth of an inch, otherwise when the valve be-
comes hot it will not seat properly, poor com-
pression being the result. In grinding a valve
there is no occasion to use force, and the grind-
ing should be done lightly, the valve being
lifted from time to time so that any foreign
substance in the emery will not cut a ridge in
the seat, or the valve itself. After grinding the
valve always wash out the valve seat with a
little kerosene, and be careful that none of the
emery is allowed to get into the motor cylinder.

Valves which need reseating should first be
ground in place with fine emery and oil, then
finished with tripoli and water.

A good mixture for grinding valves may be
made by using fine emery and cylinder oil
mixed in the form of a paste convenient to
work with.

Exhaust- Valve Sticking. Sometimes a mo-
tor may suddenly stop from the failure of the
exhaust-valve to seat properly. This may be
due to the warping of the valve, through the
motor having run dry and become hot, or it
may be from the failure of the valve spring, or
the sticking of the valve-stem in its guides. The
valve should be removed, and the stem cleaned
and scraped, or straightened if it requires it,
until it moves freely in the guide, and the
spring is given its full tension. If the valve
still leaks so that the motor will not start or

680 The Automobile Handbook

develop sufficient power, the valve will have to
be ground into its seat.

Valve Grinding. To grind a valve pro-
ceed as follows: First loosen the lower end of
the valve spring from the lower end of the valve.
This may be held by a number of different de-
vices such as washers with pins under them, or
grooves cut in the valve steam into which a
washer slips. To loosen the spring it must first
be pried up from the bottom, that is, so the end
of the spring is held away from the end of the
stem. This may be done by a special valve
spring lifter or the repairman can make a forked
lever so that the prongs fit on each side of the
stem and lift the spring by resting the lever
on some solid piece. Sometimes the spring can
be lifted by taking a common screwdriver and
using it to pry with. Before the spring can be
raised, however, the cap that covers the head of
the valve must be removed or at any rate the
head must be reached. Now take a "screwdriver
or hammer handle or a piece of wood and wedge
it into the valve pocket so that the head of the
valve cannot lift. If this was not done the
whole valve would lift when you pried up on the
spring.

After the spring is pried up out of the way
remove whatever locking device was holding it
and tlien the valve may be taken out of the hole
above llie valve head by letting the stem slip
through tlie spring and locking parts. You can
now examine the face and seat and you will

The Automobile Handbook 681

probably find them pitted. Also examine the
stem, and if it is dirty or covered with soot
(called carbon in the automobile business), it
should be scraped clean with a knife blade or
some sharp instrument. There must be no ridges
on the valve stem that might keep it from seat-
ing the valve properly.

A valve stem must never be oiled or greased
under any conditions. They are designed to
work dry.

The valve is ground by placing some cutting
material between the seat and face and rubbing
them together. Valve grinding material may
be made by taking emery powder of a fine grade
and mixing it with enough engine lubricating
oil to make a rather thin paste, or it may be
made by mixing the emery with lubricating oil
and kerosene. It may also be made by mixing
powdered glass with a thin oil into a paste, this
being used mostly for finishing the operation.
If a very fine fit is desired a paste can be made
with crocus powder and oil. A rather coarse
paste is used at first if the surfaces are badly
pitted and the finer, smoother pastes are used
for finishing.

After making the paste take a cloth (not a
piece of waste), tie a string to it and stuff the
cloth into the opening from the valve pocket to
the combustion space. This is to keep the grind-
ing material out of the cylinder, where it would
do great harm.

On the top of the valve head you will find a

682 The Automobile Handbook

slot for a screwdriver or else some holes that
take the end of a special fork-shaped tool.
These let you turn the valve face on the seat,
and you will need a tool that fits the particular
valve head you wish to work with. You will
also need a small can of gasoline or kerosene
handy so that the grinding compound may be
washed from the valve and seat.

The operation of valve grinding consists of
placing a small amount of the grinding com-
pound evenly on the face but not very thick.
What you can easily pick up on the tip of a
pocket knife blade is plenty at one time. The
valve is now placed in the cylinder or part that
it came out of so that the face rests on the seat.
Now take the tool that turns the valve and turn
the valve about half way around and then back
again. Do this several times.. Do not use much
pressure as the pressure forces the grinding
compound from between the face and seat and
makes the work slower.

After making several half turns the valve
head must be raised and turned to a new posi-
tion while it is not touching the seat, and then
the operation is repeated. If you do not raise
the valve from the seat every few half turns you
will make ridges on the face arid spoil the job.
Also, if you turn the valve round and round
without reversing the motion and raising it you
will spoil the work. In order to raise the valve
from the seat e\^Ty ouxe,^ vo. ^ ^\c^fc -j^nj. <»an
take a light spxm^ Al\v^V ^\s. ^tq>m^^ ^^ %\fc^ ^^^

The Automobile Handbook 683

place it on the valve stem just under the head.
This spring should rest on the metal* of the cyl-
inder at its lower end and hold the valve about
a half inch off the seat. When you press on
the valve grinding tool the valve will be pressed
down onto the seat, but when you release the
pressure it will raise again and you can turn
to a new position without pushing up on the
stem from below.

The valve must be ground for a few minutes
and then washed off and carefully examined.
When the face, and seat are a clean even light
gray all around and have no marks or pits or
rings at any point the job is finished and the
valve should be gas tight.

The next thing to do is to test the valve for
tightness. This can be done by placing pencil
marks at short distances all around the face and
then pressing the valve down and turning it
once around. If the marks are all off the face
it will be tight. You can also pour gasoline or
kerosene on top of the valve and watch for it to
run down the stem. If it does not leak through
it is tight.

Now wash every trace of grinding material
from the valve and the seat and valve pocket
and replace the valve with the spring and the
valve cap.

684 The Automobile Handbook

Valve Clearance. A large number of motors,
especially old ones, are unnecessarily noisy be-
cause of superfluous clearance between the
valve lifters and the valves, and a great part
of the noise may be eliminated simply by the
expenditure of a little time and care in reduc-
ing this clearance to the minimum. Every valve
cam, no matter what its shape otherwise may
be, is tangential at the first and last portions of
the valve's movement. The sooner the valve
takes hold of the cam on the lift, and the later
it lets go on the descent, the slower will be the

Fig. 320

movement of the valve at these instants, and
the less will be the shock both of the lifter on
striking tlie valve stem, and of the valve head
on meeting its seat.^ Fig. 320 shows this clearly.
The tangent line A B starts at A, and during
the are D C Ihe rise of the cam amounts only
to a minute distance A D.

The objection to an excessive clearance is not

The Automobile Handbook

685

simplj* the vertical hammering, but the sidewise
pressure imposed on the valve-lifters by the
cams, particularly at the instant of opening the
exhaust-valves. If it were possible to operate
the valves with no clearance whatever, and if
there were no lost motion, and if the whole
mechanism were ideally rigid, the line of pres-
sure of the cam at the instant could be said to

Fig. 321

be vertical, and there would be no side thrust
till the valve was off its seat and the pressure
of the gases on the valve was partly equalized.
As the matter actually stands, however, there is
a side thrust which is considerably increased
by unnecessary clearance, as comparison of
Figs. 321 and 322 clearly shows. In Fig. 321
there is no clearance, and the tangent to

686

The Automobile Handbook

the line of contact is horizontal. In Fig. 322
there is a clearance, AB. The thrust acts at
right angles to the tangent along the line C D,
and if C E represents by its length the force
required to overcome the pressure on the valve
and the force of the spring, there is a horizontal
thrust equal to D E. It goes without saying

Fig. 322

that valve-lifters thus adjusted will wear loose
in the guides faster than they should. As the
gas pressure on the valve head may amount to
30 or 40 pounds per square inch the instant be-
fore the valve is open, there is an evident tend-
ency to wear a hollow in the cam at the pre-
cise point where it starts the exhaust valve from
its seat. Evidently, moreover, the smaller the

The Automobile Handbook 687

clearance, the greater will be the leverage of
the cam, and the smaller will be its wearing
tendency.

The precise amount of minimum clearance is
hard to state arbitrarily. The thickness of a
business card or about 10-l,000th of an inch is
ample allowance for the expansion of valve
stems for the average length.

Valves — Lead of. The higher the speed of the
motor the greater the necessity for giving both
the exhaust, and the inlet valves what has come
to be known as a **lead," in that they open
before the completion of the particular part of
the cycle that they are intended to perform. It
must be borne in mind that time is required to
set a thing in motion and to stop it, regardless
of its form or weight, and this is true of a gas,
which has inertia the same as other substances.
Further, an appreciable period, thougli very
short indeed, is required for the creation of the
vacuum in the cylinder. The gas does not rush
into the combustion chamber the moment the
inlet valve opens ; the piston must have traveled
downward 'a bit before this takes place and the
column of gas then rushing in attains an in-
creasing velocity as the piston approaches the
lower center. In fact, it is at its greatest speed
when the piston reaches the lower dead center
so that the first part of its return travel has
little or no effect on the incoming gas, which
accordingly continues to pour into the cylinder,
until the piston reaches a point on its upward

688 The Automobile Handbook

stroke, where its compression is sufficient to
overcome the Ineitia of the stream of gas, and
this is the point at which moat designers of

Fig. 323 Fig. 324

Inclined POP,... V.l,e ^.p^'/l^^-

high-spefd engines set the inlet valve to dose,
IliiiM permitting of the suction of the greatest
possibk' riuantity of fresh gas.

The Automobile Handbook 689

Valves, Inlet, Diameter and Lift of. For
a motor of any desired bore and stroke, and
speed in revolutions per minute, the following
formula may be used to determine the diameter
of the valve opening :

Let B be the bore of the motor cylinder in
inches, and S the stroke of the piston also in
inches. As R is the number of revolutions per
minute and D the required diameter of the
valve opening, then

BXSXR

15,000

Example : Required the diameter of the ad-
mission-valve opening for a motor of 4V2-inch
bore and stroke at 1,000 revolutions per minute.

Answer: As 4^/^ multiplied by 4l^ and by
1,000 equals 20,250, then 20,250 divided by 15,-
000 gives 1.35 inches as the diameter of the
valve opening.

In practice, a motor of 4% inches bore and
stroke has, with a mechanically operated ad-
mission-valve, an opening of li/^ inches diame-
ter and runs up to 1,200 revolutions per minute.

The upper view in Fig. 325 shows clearly the
diameter D referred to in the formula, as some
persons are in the habit of referring to the out-
side diameter of the valve itself instead of the
opening in the admission-valve seat. The cen-
ter view in Figure 8 shows an admission-valve
with a flat seat, which is known as a mushroom
valve, on account of its shape. For this form

690

The Automobile Handbook

of valve to give a fuU opening the lift shouk
be exactly one-fourth of the diameter of tli(
valve opening: therefore if L be the reqiiirec
lift of the valve, and D the diameter of thi
valve opening, then

D
L = — = 0.25 D

Fig. 325

The lower view in Fig. 325 shows a vai
witli a Ix'vcl seat, having an angle of 45 degree
wliicli is most commonly used. The lift of tli
form of valve rcMiuires to be about three-eight
of the (liamoter of the valve opening; that is,
L is th(» rcMiuired lift of the valve and D tl
diameter of the valve opening, then

The AiUomobile Handbook

691

Lz=

2.83

= 0.35 D

The bevel-seat form of valve is to be pre-
ferred to the flat-seat or mushroom type of
valve, for two reasons: first, that it is more
readily kept in shape by regrinding, and sec-
ond, it gives a freer and more direct passage
for the gases, as will be plainly seen by refer-
ence to the lower view in Figure 325.

Table 12 gives the correct diameter of valve
openings for motors from 3 by 3, to 6 by 6 inches
bore and stroke, with speeds from 900 to 1,800
revolutions per minute, and piston velocities of
600, 750 and 900 feet per minute, for mechan-
ically operated admission-valves.

TABLE 12.

DIAMETER OF MECHANICALLY OPERATED ADMISSION-VALVES.

•

■

-t->

Piston Speed in

Feet per Minute

600

750

900

1— <

' ^6 ■

Pi •
0)

P. •

bi)

m 3

4->

CO 3

> C

ce-^ <i>

> C

d-^ ^

> a

ci-^ '^

0) -^

iS c(3 ft

OJ-'H

•f-i 03 Oi

Or^

•« TO P,

p>o

«:^

p>o

«:^

Pf>o

3 1

1200 1

0.72

1500 1

0.90

1800

1.08

3J 1

1030

0.84

1285 1

1.05

1570

1.26

4 1

900

0.00

1125

1.20

1350

1.44

800 1

l.OS

1000 1

1.35

1200

1.62

720 1

1.20

900

1.50

1080

1.80

r>i

(\Tu) j

1.32

820 1

1.65

965

1.95

000 1

1.44

750

1.80

900

2.16

Atmospheric or suction operated admission-
valves require to be of somewhat larger diame-

692 The Automobile Handbook

ter than mechanically operated admission-
valves, for two reasons : first, that the incoming
charge has to lift the valve from its seat and
keep it suspended during the suction stroke of
the motor piston, and secondly on account of
the resistance offered by the valve spring,
which tends at all times to keep the valve on its
seat. For an atmospherically operated admis-
sion-valve which will insure practically a full
charge in the motor cylinder the formula
should be

BXSXR
D =

12,750

The proper diameter for atmospherically
operated admission-valve openings may be
readily found by increasing the required diam-
eter given in the above table for mechanically
operated admission-valves, by 15 per cent.

Example : What should be the correct diam-
eter for the atmospherically operated admis-
sion-valve of a motor of 4^/4 inches bore and
stroke, with a piston velocity of 750 feet per
minute ?

Answer: Under the column headed 750 and
opposite 4^/^ by 4^^, the diameter given is 1.35.
Then 15 per cent of 1.35 equals 0.20, which,
added to 1.35, gives 1.55 inches as the correct
diameter for the valve opening under the con-
ditions given.

Admissiox-valves, Forms of. Figs. 326 and
327 are two forms of combined admission-valye

The Automobile Handbook

ind valve cage or chamber. Fig. 326 has the
jilet on top and Fig. 'S21 on the side. Figs. 328-
J29 show two forms cf detachable or remov-

The Automobile Handbook

Fig. 328
able admission valves. The one shown in Fig.
329 may be removed from the motor without
disconnecting the admissioc-pipe, as it screws

i(ili) the c'otiiliustion chamber, and has openings
jiroLind fhi' lower portion for the admission of
Ihc exjilosive dinrge to the valve.

The Automobile Handbook 695

Vulcanizing. See Tire Vulcanizing,

Watt-Hour— Definition of. A current of one
ampere flowing in an electric circuit, with an
electro-motive force of one volt, is equal to
one volt-ampere or one watt. The voltage of a
circuit, multiplied by the rate of the current
flowing in amperes, gives the rate of work, or
energy expended in watt-hours.

It is oftentimes found that electric lamps for
automobile lighting are rated according to their
consumption in watts rather than directly in
amperes. The number of candlepower secured
from each watt consumed will vary according
to the size of the lamp iri candlepower, the
material of which the filament is made and the
type of bulb, whether vacuum or nitrogen. A
small bulb with tungsten filament will use from
1.10 to 1.25 watts per candlepower, and this is
reduced until in the largest candlepower the
rate is about 0.95 watts. The consumption with
<^arbon filaments is about two and one-half
times that with tungsten. Nitrogen bulbs use
less current than the vacuum type.

Welding — Autogenous. This process consists
of welding, or, more correctly speaking, melt-
ing together metals by means of the oxyacety-
lene flame, the temperature of which almost
rivals that of the electric arc, being 6,300 de-
grees Fahrenheit. The facility with which it
can be handled as compared with most other
methods makes its commercial application com-
paratively simple. The possibilities attendant
upon the use of a flame of such high tempera-

696 The Automobile Handbook

ture can be realized when it is remembered that
the melting point of steel is about 2,570 degrees
and that of platinum, one of the most refrac-
tory metals, is only 3,227 degrees Fahrenheit.
Its chief field of usefulness is in combining such
metal parts as would ordinarily be riveted, in
welding small parts together, in repairing bro-
ken or defective castings and for cutting metals
of any nature or size that occasions demand.

As it is possible to unite many dissimilar
metals, and with a heat so localized that neigh-
boring parts are not affected, autogenous weld-
ing has already found an extensive application
in motor car repair work. Broken crankcases
or other parts can be united and made practi-
cally as strong as new. The method of holding
the pieces of a broken aluminum case, for exam-
ple, is to clamp them into position temporarily
while clay is packed around the parts and
heated sufficiently to drive out the moisture,
thus forming a solid support for the parts as
well as a kind of mould. A series of holes are
usually drilled at the crack, or the edges of the
pieces are roughly beveled so, as previously ex-
plained, the metal can be built up from the bot-
tom. Tn some instances lugs or peculiar shaped
projections may have been completely worn off
or destroyed, when it becomes necessary to build
up now ones with additional metal. In repair-
ing a cracked watorjacket, after the edges of
the crack have been prepared, it is customary
to use copper instead of iron wire for the filling

The Automobile Handbook 697

metal as it flows at a lower temperature and
adheres very positively. In ease there is dan-
ger of warping, due to local expansion, the
entire cylinder is heated before operating
upon it.

Wheels. The wood work of all wheels should
be of selected grades of second growth hickory,
or equally good growths of other hard woods.
In the driving wheels the twisting moment of
the motor is transmitted to the spokes of the
wheels, and this torsion must be resisted by
the wood at the miter, therefore, if the hub
flanging is not clamped tight there is danger of
the joints ''working,*' which will soon lead to
something worse. When the hub clamping
bolts are tightened up they should be so pinned
that they will not turn with the nuts because
if the bolts do turn it will be impossible to
apply sufficient pressure, and the clamping ef-
fort will be insufficient. Fig. 332 shows a hub
in which the clamping bolts are prevented from
turning by means of a triangular shaped exten-
sion just under the bolt heads, which engages
a slot in the flange. In this hub the flange is
made integral with the brake drum, which also
serves for the sprocket wheel, and the torsional
effort is taken by integral metal at all points,
thus relieving the wood work from shock. The
nuts used on the clamp bolts shown in Fig. 332
are castellated, although it is not necessary to
use castellated nuts unless the flanges have to
be removed, which in modern construction is

698

W-i^Aq-A

Fijr. 330
Rear Wlieol Spoke, Snowing Proportions

The Automobile Handbook

the- exception, rather than the rule. In ordi-
nary practice if the wood ia thoroughly sea-
soned, plain nuts, if screwed up tight will hold
without resorting to the method so common in
shop practice of riveting the ends of the bolts
over the nuts. The elastic nature of the wood
will serve to hold the nuts in place. Regard-
ing spokes, a certain symmetry of contour is
aecessary if they are to be machine made. Fig.

Fig. 331

Settion of a Hub at the ifiter Showing Depth of Flange

and Method ot Clamping

330 shows a spoke in which all the i
known to wheel making are embodied, and the
depth of flanging is that which experience dic-
tates as adequate. The dimensions of the spoke
are shown in detail in the cut. The brake drum
is bolted to the spokes at a considerable radius,
thus eliminating excess strain on the wood
work.

The strength of the spoke depends in a large

Fip 332
Tliriujrli Rcir ^^l 1 \Mtli Combinfltion Bnika
Driiiii in I Intipi FInnge

The Automobile Handbook

701

sure upon its thickness in the axle plane at
tiub flange, which in Fig. 330 is 1% in. The
nd point of importance is at A, B, where
largest diameter is also 1% in., but in the
e of the wheel instead of the axle. At the
n engaging the felloe, this spoke is 1% in.,
s major diameter, which is the plane of the

Fig. 333

ction of Felloe Depictinsf Tenon and Methctd of

Wedging Wlik-li will Split tiie Felloe

, whili" in the plane of the wheel the minor
leter of the elliptical section is 1 3/16 in.,
3h dimension prevails in this plane from
t A, B, out to the felloe. In some types of
:es the section at the cngagempnt of the fel-
:s round, and reduced gradually to the sec-
at A, B. Pig. 331 shows a section of the

702 The Automobile Handbook

hub of another type of wheel, in which the
radial depth of flanging is 2i/i in., and the axle
thickness of the wood is 2^^ in. This wheel
may be used on a 60 II, P. ear, and will serve as
a safe example of depth of flanging, as well as
a guide in fixing the shear section of the spokes
for stresses induced, when cars of great power
skid, provided the wheel is not dished. Fig.
333 shows the same spoke at its engagement
with the felloe, indicating the manner in which
the spoke is wedged into the felloe.

Figure 334 shows the Schwarz type of wheel,
indicatiiifr the method of overlapping the mi-
ter, Jhus making it, possible to true up the wood
work independent of the huh. Fig. 335 shows
a section of the huh, spoke and felloe of a
dished wheel, and it will be seen that the fellofi
is not in the pinne of tho miter, and the dish of
the whoi'l IS iiutward. When a car is running
at a coiiiparativcly high speed rounding a
onrvi', the outer wheels are itressed in such a

The Automobile Handbook

703

nner that the tendency is to set a dish in
m exactly opposite to the dish given by the
eei maker.

The shorter the spokes are, the greater will
! dishing have to be in order to insure that
I spokes will be enough longer than the radial

Fig. 335
ection of a Wheel Showing the Dish, Which Has
Strength to Resist Skidding and Lateral Stresses

tance from the hub end of the spokes to the
iring against the felloe, to serve as members
compression, and the rim on the felloe will
re to do the work. As the cut shows, the ex-
a length of spokes marked '* difference, '*
resents the versed sine of the angle of the
kes.

704 The Automobile Handbook

WheelB, Steel- Steel is estensivelj a
the manufacture of wheels for aut.ni
These types include steel disk wheels de
especially for trucks; wheels with "Si
spokes, built for use on either trucks ot
mobiles; also wire wheels, which will
scribed later on.

Figure 336 'shows the design and coi
tion of a resilient spring steel wheel. !
sists of a spec!
which may be
or machined to
standard asle,
of single leaf !
of specially
chrome van.
steel, and a ri
holds the ends
!it !^L., „ springs ^ and
^ serves as earr
the tire.

These springs or spokes are. carried
(tenter bearing, and they carry the load
torsion at all times. In the automobile
there are twelve of these spokes, eao
being made of sufficient width and
enough to take care of the load for whi(
designed. Provision is made for a for
cent overload in the design of the s
which means that the steel will nei
strained beyond its elastic limit, Thi
vision against overload prevents fracture

The AutomoMle Handbook 705

spokes under load vibration or in ordinary road
travel.

Wire Wheels. The development of the wire
wheel has been very rapid during recent years.
The invention of the wire wheel created a
radical change in the method of load carrying,
due to the fact that, instead of the compressive
strain brought to bear upon a few spokes
underneath the axle, as is the case with the
ordinary type of wheel, there is a tensional
stress on a large number of wire spokes, and
the weight is thus held in suspension by the
wire wheel with its steel rim and steel wire
spokes.

Although the pneumatic tire is a great ab-
sorber of jolts, if the wheel strike an obstruc-
tion the shock of which is beyond the capacity
of the tire to absorb, and if the wheel is fitted
with rigid spokes, this shock is passed directly
to the axle and from thence to the car springs,
and unless these are equipped with efficient
shock absorbers, the passengers are sure to
feel the effects of rough riding. On the other
hand the spokes of the wire wheel all act as
a complex yet effective shock absorber, and
an this way tend to reduce in a large measure
the annoying effects of these vibrations. An-
other advantage in connection with the use of
wire wheels is that the wheel itself, owing to
its construction and the nature of the material,
acts as an effective tire cooler, which is not
the case with the wooden wheel, for the

706 The Automobile Handbook

reason that the spokes of the latter do not
tend to radiate the heat generated in the tire
while running, consequently this heat must
radiate from the tire and rim and the process
is a very slow and ineffective one. Regarding
the two important features of durability and
lightness of weight, experience has demon-
strated that the wire wheel compares favorably
with the wooden wheel. It is claimed that the
lightness of the wire wheel is an important
fayctor in reducing the tendency to gjo'oscopic
action, which is always present in wheels run-
ning at high speeds.

The number of spokes in each wheel and
method of their attachment to the hub and
the rim vary according to the ideas of the
designers. In some types of wire wheels the
rim only is demountable, while other types
have all the functions of a demountable rim
and a demountable wheel. The Lindsay twin
wire wheel (a semi-sectional view of which is
shown in Figure 337) is a notable example of
the latter type. The component parts of the
Lindsay wheel are assembled into two complete
self-contained sections or units, hence its name.
There are eighty spokes that connect the rim
parts and hub parts together. The wheel as
a whole is mounted on the inner fixed hub and
interlocks with it, also interlocking with the
web of the brake drum. The form of structure
gives two rows of spokes laced in each side
of the wheel, thereby taking care of the side

The Autwnobile Handbook 707

thrust from either side equally. The tire rim
is mounted between the two conical felloe
rims of the two wheel sections and is held in
place by the rim bolts, thus making it secure.
Since the tire rim is secured in place between

Pig. 337
Lindsay Twin "Wire Wheel

the two wheel rims by means of rim bolts it
is evident that both wheel and tire rims will
expand and contract together. By removinp;
the rim bolts with a wrench and taking off
the hub dust cap, the outer twin wheel can be
dismounted, leaving the inner wheel intact,
thereby releasing the tire.

Another type of wire wheel is the Spranger,

708

The Automobile Handbook

a view of which is shown in Figure 338, In
this wheel there are 48 spokes interlaced in
a simple cross system and equipped with a de-
mountable rim, which like the demountable

Fig. 338
Spranger Wire Wheel

rim oil a wooden wheel, can be removed for
the cliaHfriiig of llie tire. The Spranger wheel
itself is jiot <leiiiouiitahle. and when installing
tlioMc wheels on his car the owner obtains a
ooniplcte new set of bearings, brake drums, and

The Automobile Handbook 709

hub caps. This type of wheel has recently
come into extensive use on the Ford and Chev-
rolet cars. In the construction of the Spranger
wire wheel a special type of channel is used.
This channel is of structural steel, and is 1^
inches in width by % inch in depth, and into
it the spokes are laced. The method of lock-
ing the rim to the wheel is as follows: each
rim has six steel blocks securely riveted to it,
which prevent the rim from rising or losing
position, while at the same time there is no
wedging action.

In Figure 339 is presented a view of the
Houk wire wheel, made by the Wire Wheel
Corporation of America.

Each wheel contains 72 steel wire spokes,
each of which, before the wheel is assembled,
is subjected to a test and must withstand a
strain of 3,200 pounds. The spokes are ar-
ranged in triple rows as will be seen by the
illustration, the triple lacing thus providing a
set of spokes to take up the strain from any
direction.

One end of each wire spoke is securely riv-
eted to the rim, while the other end is secured
to the hub in its proper location also by riv-
eting. It is claimed that the interlacing of
the spokes is of such a nature that three-
fourths of them are continuously in use, sup-
porting the load by suspension. In case of
tire trouble, such as a puncture or blowout,
the wheel can be removed in a few minutes

710 The Automobile Handbook

by merely jacking up the ear and unscrewing
(nio nut. The wheel with the damaged tire
call then be replaced by the extra wheel with a
frood tire.

Mention has already been made of the in-
eruasod e£6cieney of the wire wheel as a tire

Fig. 339
Ilouk Wire Theel

onolir. as (.'ompaivd with the wooden wheel.
.\ii(itbi'r point In favor of wire wheels is the
small ari'a of siioke surface to be acted upon
by Till' atmoRihlicre in its resistance to the
iiiDVi'iiK'nt (if tlic car. This resistance is always
|ii'i>si'iit, ami till' f-'rcatcr the area of the surface
llijil is presented liy a moving body for the
aliiiiisphui'ic |iressni-e to act upon, the greater
will be the resistance tending to retard that
ninvenient.

INDEX

[Note: This Index does not aim to give a complete
list of subjects treated in The Automobile Handbook.
The subjects grenerally are arranged in alphabetical
order throughout the book. This index includes the
sub-headings under the principal general headings.]

Page

Acetylene gas 9

Adams motor 11

Admission valves , , 692

Air, compressed, properties of 16

Air-cooling systems 255

Air resistance 20

Alcohol 22

Allis-Chalmers equipment 569

Alloys, composition of 27

Aluminum 2,6

Ammeter, construction of 28

Annular ball bearings 115

Anti-freezing mixture 32

Armatures, dynamo 38

Assembling a car 40

Atwater-Kent ignition system 372

Autogenous welding 697

Auto-Lite equipment 575

Automobile driving 42

Automobile tools 53

Axles 67

front 70

rear 77

semi-floating 67

three-quarter floating 67, 81

full floating 68

Ball bearings 109

Band clutch 232

Batteries 86

dry 87

The Automobile Handbook

Papre

storage 91

storage, starting and lighting types. ... 103

Bearing, ball 109

roller 121

Bearings, hard and soft 117

Bendix drive 125

Berline or berlin 134

Bevel gear, differential 267

Bijur equipment 578

Bodies 128

classification of 129

Bosch equipment 583

Bosch magnetos 411

Brakes 137

proper use of 44

Brake linings 142

Brazing 148

Breakdowns and their remedies 58

Chain broken 68

Circulating pump leakage 58

Cranking with safety 59

Radiator leaking 62

Rods or links broken 64

Trembler blades broken 65

Cahriolet 136

('Minshaft 149

Car])()n deposit 151

Car])uretors, principles of 154

float feed 159

Hollv, model G 170

Holly, model H 167

inspection 166

Kingston 173

Krobs 175

Master 177

Rayfield 178

Sfhebler 185

spraying 161

Stromberg 189

venturi tube 161

Zenith 203

Car inspection 60

The Automobile Handbook

Page
Centrifugal pump 531

'hange speed gearing 206

Hutch 230

Jlutch troubles 240

/Ombustion chamber 244

/Ombustion, heat of 346

/Ommercial car bodies 136

Commercial vehicles 130

Commutators 245

lompensating joints 482

!ompression 248

lompressed-air starters 565

Condenser, use of 250

lone clutch : 233

lonnecticut ignition system 381

onstruction of engines 278

ooling systems 254

!oupe 135

^alton's laws 262

elco equipment 585

elco ignition system 386

•ifferential gears 264

isc valves 678

isc clutch 237

isk clutch 237

ixie Magnetos 428

on*ts 51

ouble-disk friction drive 209

riving 42

ry batteries 87

ry cells for ignition 59

yueto and Entz equipment 607

Isemann magneto 432

Lght-cylinder engine 308

lectricity, forms of 274

lectric gear shift 511

lectric motor vehicles 516

Qgines 278

construction of 278

eight and twelve-cylinder types 308

The Automobile Handbook

Engines (continued) Page

explosive motors 278

four-cycle motor 296

fuel consumption 301

internal combustion 278

knight sliding sleeve type 303

offset crankshafts 284

pistons 287

piston displacement 289

pistons, length of 289

piston materials 288

piston position 289

piston rings 293

explosive motor engines 278

two-cycle motor 298

Five-plate clutch 239

Float feed carburetor 159

Fluxes for soldering 547

Flywheels 320

Ford magneto 446

Four-cycle motor 296

Friction drive 207

Fuel consumption 301

Fuel feed, vacuum 327

Gasoline pipe broken 59

Gear changing 43

Gears 341

Gears, differential 264

differential casing 59

Gear shift, electric 511

magnetic 509

Gearless transmission 341

Gray & Davis equipment 610

Herz magneto 448

Holly carburetor, model G 170

Holly carburetor, Model H 167

Horsepower 350

The Automobile Handbook

PagB

Ignition commutators 246

Ignition systems 3GS

Atwater-Kent 372

back flring, causes of 83

induction coll 3B9

jump Fpark coil 364

secondary spark coll 366

timing 369

Ignition, -wlien to advance 49

Ignition, when to retard 43

India rubber E35

Induction coll 359

Inspection, carburetor 166

Internal combustion engines 278

Joints, compensating 482

Joints, knuckle 484

Joints, universal 485

Jump spark coll 364

Kingston carburetor 173

Knlgbt sliding sleeve type engine 303

Knocking, locating cause of 488

Knuckle joints 484

Krebs' carburetor 175

Landaulet or landau 134

Lighting systems 665

Lubricntlon *91

Lubricating systems 506

force teed 608 .

force feed and splash 606

full force feed 606

splash 506

Ford flywheel oiling system 501

Hancock mechanical oiler 496

McCord mechanical oiler 495

pierce- Arrow oiling system 600

The Automobile Handbook

Pag-e

Magnetic gear ehift 509

Magnetic transmission 224

Magneto, Bosch 411

Dixie 428

Eisemann 432

Ford 444, 446

Herz 448

Mea 453

Remy 458

Simms 465

Splitdorf 468

U and H 475

Magneto type ignition system 405

Bosch magnetos 411

Connecticut 381

Delco 386

Dixie 428

Eisemann Magneto 432

Ford 446

Herz 448

Magneto type 405

Mea 453

Remy 392

Remy magneto 458

Simms 465

Splitdorf 468

U and H magneto 475

Westinghouse 396

Master carburetor 177

Mea magneto 453

Miss fire cylinder 61

North East equipment 620

Nuts and screws, how to loosen 61

Offset crankshaft engines 284

Overheating 259

causes of 259

effects of 261

remedies for 261

Owen magnetic transmission • • 226

The Automobile Handbook

Passenger bodies 136

Pistons 287

Piston displacement 2S9

Pistons, length o( 389

Piston materials 288

Piston position 289

Pleton rings 298

Pitted valves 678

Planetary change speed gear 218

Pounding, causes o( 527

Prelg&ltlon, causes of 628

Priming 62

Radiator leaking 62

Rayfleld carburetor 178

Remy battery system '. . 392

Remy equipment 621

Remy Ignition system 392

Remy magneto 458

Reversing 44

Roadster 133

Rods or links broken 64

Roller bearing 121

Rotary valves 676

Runabout 133

Rusbinore engine starter 627

Rushmore equipment 627

RuBhmore lighting system 629

Schebler carburetor 185

Secondary spark coll 365

Sedan 134

Selective sliding gear 218

Semi-floating rear axle 67

Skidding 46

Shop klnk3 S36

Slmms magneto 466

Simms-Huff equipment 630

Sliding gear 216

Sliding sleeve type engine 303

Spark Plugs 660

The Automobile Handbook

Spark, regulation of 47

Spraying carburetor 161

Specific gravity 556

Speedster or raceabout 133

SpUtdorf-Apelco e<iulpinent 632

Splttdorf magneto 468

Springs 556

Squeaking springs 65

Starting and Hghting systems 665

Allls-Ch aimers equipment 569

Auto-Lite equipment 576

Bllur equipment 57S

Bosch equipment 583

Compresaed'alr starters 665

Delco equipment 585

Dyneto and Bntz equipment 607

Gray & Davis equipment 610

North East equipment 620

Remy equipment 621

Rushmore equipment 627

Rushmore engine starter 627

Rushmore lighting System 629

Slmms-Hufl! equipment 630

Splitdorf-Apelco equipment 632

U. S. L. equipment . . . ; 636

Wagner equipment 640

Westinghouse equipment 645

Steering knuckles 75

Stewart vacuum fuel feed tank 327

Storage batteries 91

starting and lighting types 103

Stromberg carburetor 189

Taxicab 136

Timing 369

Tires, care and repair 662

Tire vulcanizing 666

Tools, automobile 63

Torpedo 132

Touring car 132

Town car 136

Toy tonnean 132

Transrai'islon, gearless 841

magnetic ....• 124

The Automobile Handbook

Transmission (continued) Page

sliding gear 220

Trembler blades broken 65

Truck bodies .-'TT^IZQ^

Twelve-cylinder engine 308

Two-cycle motor 298

TJ and H magneto 475

Universal joints 485

Useful hints 544

U. S. Lf. equipment 636

Vacuum fuel feed 327

Valves 674

disc 678

pitted 678

rotary 676

sliding sleeve type 303

Valve clearance 684

Valve grinding 680

Valves, inlet, and lift of 689

Valves, lead of 687

Venturi tube carburetor 161

Vulcanizing of tires 666

Wagner equipment 640

Water circulation 257

Water circulating pump 532

Water pump 529

Welding, autogenous 695

Westinghouse equipment 645

Westinghouse ignition system 396

Wheels 697

Zenith carburetor 203

Books ThatReattyTeach

you the things you want to know, and in a
•imple, practical way that you can understeuid

Our illuslrated catalogue, which will be sent you free upoa
request, tells all about the Practical Mechanical Books (at
Home Study that wt pabfaL
There are popular t^ieed
books oD the operabon of
trains and station worlc, prac-
tical mechanical drawing and
machine deigning, paltem
malting, electrical railroading,
power stations, automobfles,
gas engines, electrical wiring,
aimaUire and magnetwinding,
dynamo tending, elementary
electricity, wireless telegraphy
and telephony, carpentry and
architecture, concrete con-
struction, plumbing and heat-
ing, sign and house painting,
amusements, etc., etc
No matter what your ambi-
tion or desire for aoiowledge
may be, we publish books written by authorities in
their different lines that will ^ve you just the training and
infoimation that you want and need.

FREDERICK J. DRAKE & Ctt

DRAKE'S MECHANICAL BOOKS

♦Title I Style | Price

Electrical Books

Electrical Tables and Engineering

Data *Lea. $1.50

Electrical Tables and Engineering

Data *Cloth 1.00

Motion Picture Operation *Lea. 1.50

Motion Picture Operation * Cloth 1.00

Alternating Current Lea. 1.50

Alternating Current Cloth 1.00

Wiring Diagrams and Descrip-
tions *Lea. 1.50

Wiring Diagrams and Descrip-
tions ♦Cloth 1.00

Armature and Magnet Winding. .*Lea. 1.50

Armature and Magnet Winding. .*Cloth 1.00

Modern Electric Illumination .... *Lea. 1.50

Modern Electric Illumination. .. .*Cloth 1.00

Modern Electrical Construction .. *Lea. 1.50

Modern Electrical Construction. .* Cloth 1.00

Electricians* Operating and Test-
ing Manual *Lea. 1.50

Electricians* Operating and Test-
ing Manual ♦Cloth 1.00

Drake^s Electrical Dictionary.... Lea. 1.50

Drake's Electrical Dictionary.... Cloth 1.00

Electric Motors, Direct and Alter-
nating *Lea. 1.50

Electric Motors, Direct and Alter-
nating ♦Cloth 1.00

Electrical Measurements and Me-
ter Testing Lea. 1.50

NOTE. — New Books and Revised Editions are marked*

. , y

DRAKE'S MECHANICAL BOOKS

♦Title I Style | Price

Electrical Books — Continued

Electrical Measurements and Me-
ter Testing Cloth $1.00

Drake's Telephone Handbook. . . . Lea. 1.50

Drake's Telephone Handbook. . . . Cloth 1.00

Elementary Electricity, Up-to-

Date *Cloth 1.25

Electricity Made Simple 'Cloth 1.00

Easy Electrical Experiments *Cloth 1.00

Wireless Telegraph and Telephone

Handbook Cloth 1.00

Telegraphy, Self-taught Cloth 1.00

Dvnamo-Electric Machines Cloth 1.50

Electro-Plating Handbook Lea. 1.50

Electro-Plating Handbook Cloth 1.00

Modern American Telephony. . . . Lea. 2.00

Handy Vest-Pocket Electrical Dic-
tionary Lea. .50

Handy Vest-Pocket Electrical Dic-
tionary Cloth .25

Storage Batteries Cloth .50

Elevators — Hydraulic and Electric Cloth 1.00

How to Become a Successful Mo-

torman Lea. 1.50

jMotorman's Practical Air Brake

Instructor Lea. 1.50

Electric Railway Troubles Cloth 1.50

Electric Power Stations Cloth 2.50

FJectrical Railroading Lea. 3.50

NOTK. — Now r.ooks and Revised Editions are marked*

DRAKE'S MECHANICAL BOOKS

*Htle I Style | Price

Automobile Books

Brookes' Automobile Handbook . . *Lea. $2.00

Automobile Starting and Light-
ing *Lea. 1.50

Automobile Starting and Light-
ing •Cloth LOO

Ford Motor Car and Truck and

Tractor Attachments *Lea. 1.50

Ford Motor Car and Truck and

Tractor Attachments * Cloth 1.00

Automobile Catechism and Repair

Manual *Lea. 1.25

Practical Gas and Oil Engine

Handbook *Lea. 1.50

Practical Gas and Oil Engine

Handbook 'Cloth 1.00

Farm Books

Farm Buildings, With Plans and

Descriptions *Cloth $1.00

Farm Mechanics *Cloth 1.00

Traction Farming and Traction

Engineering *Cloth 1.50

Farm Engines and How to Run

Them Cloth 1.00

Shop Practice Books

Twentieth Century Machine Shop

Practice ,', Cloth $2.00

Practical Mechanical Drawing. . . . Cloth 2.00

Sheet Metal Workers' Manual . . . *Lea. 2.00

Oxy-Acetylene Welding and Cut-
ting *Lea. 1.50

Oxy-Acetylene Welding and Cut-
ting *Cloth 1.00

20th Century Toolsmith and Steel-
worker Cloth 1.50

Pattern Making and Foundry
Practice Lea. 1.50

Modern Blacksmithing, Horse-
shoeing and Wagon Making... Cloth 1.00

NOTE. — New Books and Revised Editions are marked*

M- *

f —

DRAKE'S MECHANICAL BOOKS

♦Title I Style | Price

Steam Engineering Books

Swingle^s Handbook for Steam
Engineers and Electricians .... *Lea. $3.00

Steam Boilers, Construction, Care
and Operation *Lea. 1.50

Complete Examination Questions
and Answers for Marine and
Stationary Engineers *Lea. 1.50

Swingle's Catechism of Steam,
Gas and Electrical Engineering.* Lea. 1.50

The Steam Turbine, Its Care and

Operation Cloth 1.00

Calculation of Horse Power Made
Easy Cloth .75

Railroad Books

Modern Locomotive Engineering. *Lea. $3.00

Locomotive Fireman's Boiler In-
st ructor *Lea. 1.50

Locomotive Engine Breakdowns
and How to Repair Them *Lea. 1.50

Operation of Trains and Station
Work 'Lea. 2.00

(V)nstrnction and Maintenance of
Kailwav Roadbed and Track. . . Lea. 2.00

First, Second and Third Year
Standard Examination Ques-
tions and Answers for Locomo-
t ive Firemen *Lea. 2.00

('om})lete Air Brake Examination

Questions and Answers *Lea. 2.00

Westin<4liouse Air Brake System. Cloth 2.00

New York Air Brake System.... Cloth 2.00

Walscliaert Valve Gear Break-
downs Cloth 1.00

NOTE. — X«'w Hooks an<l Revised Editions are marked*

DRAKE'S MECHANICAL BOOKS

*¥iile ' I Style lias

Carpentry and Boilding Books

Modern Carpentry. Two volumes. Cloth $2.00

Modem Carpentry. Vol, I Cloth 1.00

Modern Carpentiy. Vol. II . . . j . . Cloth 1.00

The Steel Square. Two volumes. . Cloth 2.00

The Steel Square. VoL I Cloth 1.00

The Steel Square. VoL II. Cloth 1.00

A. B. C. of the Steel Square Cloth M

Common Sense Stair Building and

Handrailing ^ '., Cloth LOO

Modern Estimator and Contrae-

tor's Guide ♦Cloth 150

Light and Heavy Timber Framing

Made Easy Cloth 2.00

Builders' .Architectural Drawing

Self-taught.... , Cloth 2.00

Easy Steps to Arehiteetnrei • . . • . Cloth iJtO

Five Orders of Architecture Cloth 1.60

Builders' and Contractors' Gtdde Cloth 1.60

Practical Bungalows and Cottages ♦Cloth LOO

Low Cost American Homes ♦Goth LOO

Practical Cabinet Maker and F119- ' * .

niture Designer • • Cloth 2.00

Practical Wood Carving .... Cloth L60

Home Furniture Making Cloth .60

Concretes, Cements, Mortars, Plas-
ters and Stuccos Cloth L60

Practical Steel Construction Cloth ,76

20th Century Bricklayer and Ma-
son's Assistant Cloth L60

Practical Bricklaying Self-taught. Cloth 1.00

Practical Stonemasonry Cloth LOO

Practical Up-to-date Plumbing .^. . .Cloth 1.50
Hot Water Heating, Steam and

Gas Fitting Cloth 1.50

Practical Handbook for Mill-
wrights , Cloth 2.00

Boat Building for Amateurs Cloth 1.00

NOTE. — New Books and Reyiaed Editions are marked*

DRAKE'S MECHANICAL

. BOOKS

1 style 1 Price

♦Title

Painting Books

Art of Sign Painting

•Cloth $3.00

Scene Painting and Bulletin Art. .

•Cloth

3.00

"A Show at" Sho^Cards

Cloth

3.00

Strong's Book of Designs

•Lea.

3.00

Signist's Modern Book of Alpha-
bets

Cloth

1.50

Amateur Artist

Cloth

1.00

Modern Painter's Cyclopedia

Cloth

1.50

Red Book Series of Trade School

Manuals —

1. Exterior Painting, Wood,
Iron and Brick

Cloth

.60

2. Interior Painting, Water and
Oil Colors

Cloth

.60

3. Colors

Cloth

.60

4. Graining and Marbling

Cloth

.60

5. Carriage Painting

Cloth

.60

6. The Wood Finisher

Cloth

.60

New Hardwood J^'inishing

Cloth

1.00

Automobile Painting

•Cloth

1.25

Estimates, Costs and Profits —
House Painting and Interior
Decorating

•Cloth

1.00

NOTE. — New T.ooks and Revisod Editions are marked* |

DRAKE'S HOME ' STUDY BOOKS

♦Title I Style | Price

General Instruction and Reference Books

Putney's Law Library

(12 volumes) Buckram $60.00

Bookkeeping Self-taught Cloth 1.00

Complete Courses in Bookkeeping,
Including Blank Books and
Supplies Cloth 7.50

Elementary Chemistry Self-taught Cloth 1.00

Picture Making for Pleasure and
Profit Cloth 1.25

Complete Courses in Civil Service. Cloth 1.25

Felt's Parliamentary Procedure . . Cloth .60

McClure's Horse, Cattle and Sheep
Doctor 'Cloth 1.25

Practical Lessons in Hypnotism
and Magnetism Paper .50

Practical Lessons in Hynotism
and Magnetism Cloth 1.00

Chadman's Dictionary of Law. . . . i Lea. 6.00

Modern Magician's Handbook. . . . Cloth 1.50

White House Handbook of Ora-
tory Cloth 1.00

Standard Cyclopedia of Receipts. Cloth 1.25

American Star Speaker and Elo-

cutionist Cloth 1.25

Swimming and Life Saving Paper .30

Words as They Look (Webster's

System of Memorizing Easy

and Difficult Words) Cloth .50

Astrology (Were You Bom Under

a Lucky Star?) Cloth 1.00

NOTE. — New Books and Revised Editions are marked

DRAKE'S HQME-STUDY BOOKS

♦Title I Style | Price

General Instruction and Reference Boc^cs

Ropp's Calculator —

Style A. Large Size. . . .Moroccoline 1.25

Style B. With Flap Leather 1.00

Style C. Pocket Size. .. .Moroccoline .50
Style D. Vest Pocket. . .Leather 50

Albertus Magnus (Egyptian Se-
crets) Cloth 1.00

Sixth and Seventh Books of Moses. Cloth 1.00

Drinks as They Are Mixed Cloth .25

Drinks as They Are Mixed Lea. .50

Guide to Successful Auctioneering. Paper .25

Safe Methods of Stock Specula-
tion Cloth .50

Gypsy Witch Fortune Telling

Cards Per Pack .50

Mrs. Parker's Monologues and Flays

Monologues, Stories, Jingles and

Plays 'Cloth $1.00

New Monologues and Dialect Sto-
ries Cloth 1.00

Mary Moncure Parker's Plays —

Powder and Patches Paper .25

When Your Wife's Away Paper .25

Love Behind the Scenes Paper .15

Mrs. Gadabout's Busy Day. .... Paper .15

Black Art Paper .15

A Day at the Know-It-AU

Woman's Club Paper .25

The Rehearsal Paper .15

The Princess Innocent Paper ,15

A Quiet Evening at Home Paper J.5

A Colonial Dream Paper .15

NOTE. — X(^w Books and Revised Editions are marked*

Speakers _ ^. ^

"^ Cloth Paper

Comic Recitations and Readings. .$0.50 $0.25

Conundrums and Riddles 50 .25

Complete Debaters' Manual 50 .25

MjcBride's Latest Dialogues .50 .25

Little Folk's Dialogues and Dra-
mas .50 .25

Little Folk's Speaker and Enter-
tainer .50 .25

Patriotic Readings and Recitations .50 .25

Toasts and After Dinner Speeches .50 .25

Practical Ventriloquism 50 .25

Etiquette and Letter Writers

Because I Love You $0.50 $0.25'

Practical Etiquette and Society
Guide .50 .25

Brown's Business Letter Writer

and Social Forms. .50 .25

North's Book of Love Letters and

How to Write Them .50 .25

Modern Quadrille Call Book and

Complete Dancing Master 50 .25

Standard Drill and Marching Book .50 .25

Card and Sleight of Hand Books

Card Sharpers — Their Tricks Ex-
posed $0.50 $0.25

The Book of Card Tricks and
Sleight of Hand 50 .25

Card Tricks— How to Do Them. . . .50 .25

Tricks with Coins 50 .25

The Expert at the Card Table 50 .25

Hermann's Book of Magic and
Black Art 50 .25

Froderiek J. Drako ft Company's

CATALOGUE OF

Standard Up-to-Date Hand Books on
the following Subjects:

Dialogues, Recitattons, Tableaux,

Charades, Pantomimes, Mock Trials,

Bffonologiies, Drills, Marches, Minstrel
and Entertainment Books, Magio,
Palmistry, Hypnotism, Black Atfl»
Blectricity, Speakers, Poultry*
fietter Writers, Dream Books,

Fortune Tellers, Popular Dramas,
Photography, Btiquette, Danoing,
EtOt EtOt EStc E:to«

Bach book in this list is the work of a com*
petent specialist, and will be found reliablet

■zm

ikny Book Advertised in This Catalogue Sent
Postpaid, on B>eceipt of Price.
l^RBDBRICK J. DRAKE A CO.

Twentieth Century
Machine Shop Practice

By L. ELLIOTT BROOKES

•r.:Bs

a u Iter lo

8seo

12mo, cloth, 636 page*, 456 fine [tlustnlioiu, price, f2J)0

Sold by Bookxillen aenenlly. or Kst poMpaid to

iny iddroiuppn receipt of Price by thePuUi^cn

FREDERICK J, DRAKE & CO.

PUBUSHERS CHICAGO, U. S. A.

The Practical Gas &
Oil Engine hand-book

AMAVVAL o f nssrnl iif

This work glvaa (nil and
clesi instracliona on all pclnti

Potisble and Matina, Gaa ud
Oil Enzines. includinc How to
SiarE, Hc>wtoS[oD.HotTlaAd-
Jnat, HoK to Repair. How Eo
Test

PoekM aiu, «i6H.
232 pssss. With namoToni
rules and fflrnmlaa aad dit
'EFams. uidaver70illDBtrUion

Iboi- of the "Cooatmcdon of a
Gasolina Motor." and Ihs "An-
iomobilB Hand-Book."

This book has oaen wrllteD
with the inlcDtioa ot tuiDiahinl
practical inform

In their conelructiDn, operatlaD and m

tfcmo. PopulB.r Edition-Cloth. Price.
Edition do Luxe-Full Lea.tl>ar LUnih

' Mm! !.'.'.'

$1.00

1.50

Sen) Poslpald to any

Minn in th« World upon ilMOlpI of Pfic*

FREDERICK J. DRAKE & CO.

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